marlin/Marlin/Marlin_main.cpp

/**
 * Marlin 3D Printer Firmware
 * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 *
 * About Marlin
 *
 * This firmware is a mashup between Sprinter and grbl.
 *  - https://github.com/kliment/Sprinter
 *  - https://github.com/simen/grbl/tree
 *
 * It has preliminary support for Matthew Roberts advance algorithm
 *  - http://reprap.org/pipermail/reprap-dev/2011-May/003323.html
 */

#include "Marlin.h"

#if ENABLED(AUTO_BED_LEVELING_FEATURE)
  #include "vector_3.h"
#endif

#if ENABLED(AUTO_BED_LEVELING_LINEAR_GRID)
  #include "qr_solve.h"
#elif ENABLED(MESH_BED_LEVELING)
  #include "mesh_bed_leveling.h"
#endif

#if ENABLED(BEZIER_CURVE_SUPPORT)
  #include "planner_bezier.h"
#endif

#include "ultralcd.h"
#include "planner.h"
#include "stepper.h"
#include "endstops.h"
#include "temperature.h"
#include "cardreader.h"
#include "configuration_store.h"
#include "language.h"
#include "pins_arduino.h"
#include "math.h"
#include "nozzle.h"
#include "duration_t.h"
#include "types.h"

#if ENABLED(USE_WATCHDOG)
  #include "watchdog.h"
#endif

#if ENABLED(BLINKM)
  #include "blinkm.h"
  #include "Wire.h"
#endif

#if HAS_SERVOS
  #include "servo.h"
#endif

#if HAS_DIGIPOTSS
  #include <SPI.h>
#endif

#if ENABLED(DAC_STEPPER_CURRENT)
  #include "stepper_dac.h"
#endif

#if ENABLED(EXPERIMENTAL_I2CBUS)
  #include "twibus.h"
#endif

/**
 * Look here for descriptions of G-codes:
 *  - http://linuxcnc.org/handbook/gcode/g-code.html
 *  - http://objects.reprap.org/wiki/Mendel_User_Manual:_RepRapGCodes
 *
 * Help us document these G-codes online:
 *  - https://github.com/MarlinFirmware/Marlin/wiki/G-Code-in-Marlin
 *  - http://reprap.org/wiki/G-code
 *
 * -----------------
 * Implemented Codes
 * -----------------
 *
 * "G" Codes
 *
 * G0  -> G1
 * G1  - Coordinated Movement X Y Z E
 * G2  - CW ARC
 * G3  - CCW ARC
 * G4  - Dwell S<seconds> or P<milliseconds>
 * G5  - Cubic B-spline with XYZE destination and IJPQ offsets
 * G10 - Retract filament according to settings of M207
 * G11 - Retract recover filament according to settings of M208
 * G12 - Clean tool
 * G20 - Set input units to inches
 * G21 - Set input units to millimeters
 * G28 - Home one or more axes
 * G29 - Detailed Z probe, probes the bed at 3 or more points.  Will fail if you haven't homed yet.
 * G30 - Single Z probe, probes bed at current XY location.
 * G31 - Dock sled (Z_PROBE_SLED only)
 * G32 - Undock sled (Z_PROBE_SLED only)
 * G90 - Use Absolute Coordinates
 * G91 - Use Relative Coordinates
 * G92 - Set current position to coordinates given
 *
 * "M" Codes
 *
 * M0   - Unconditional stop - Wait for user to press a button on the LCD (Only if ULTRA_LCD is enabled)
 * M1   - Same as M0
 * M17  - Enable/Power all stepper motors
 * M18  - Disable all stepper motors; same as M84
 * M20  - List SD card
 * M21  - Init SD card
 * M22  - Release SD card
 * M23  - Select SD file (M23 filename.g)
 * M24  - Start/resume SD print
 * M25  - Pause SD print
 * M26  - Set SD position in bytes (M26 S12345)
 * M27  - Report SD print status
 * M28  - Start SD write (M28 filename.g)
 * M29  - Stop SD write
 * M30  - Delete file from SD (M30 filename.g)
 * M31  - Output time since last M109 or SD card start to serial
 * M32  - Select file and start SD print (Can be used _while_ printing from SD card files):
 *        syntax "M32 /path/filename#", or "M32 S<startpos bytes> !filename#"
 *        Call gcode file : "M32 P !filename#" and return to caller file after finishing (similar to #include).
 *        The '#' is necessary when calling from within sd files, as it stops buffer prereading
 * M33  - Get the longname version of a path
 * M42  - Change pin status via gcode Use M42 Px Sy to set pin x to value y, when omitting Px the onboard led will be used.
 * M48  - Measure Z_Probe repeatability. M48 [P # of points] [X position] [Y position] [V_erboseness #] [E_ngage Probe] [L # of legs of travel]
 * M75  - Start the print job timer
 * M76  - Pause the print job timer
 * M77  - Stop the print job timer
 * M78  - Show statistical information about the print jobs
 * M80  - Turn on Power Supply
 * M81  - Turn off Power Supply
 * M82  - Set E codes absolute (default)
 * M83  - Set E codes relative while in Absolute Coordinates (G90) mode
 * M84  - Disable steppers until next move,
 *        or use S<seconds> to specify an inactivity timeout, after which the steppers will be disabled.  S0 to disable the timeout.
 * M85  - Set inactivity shutdown timer with parameter S<seconds>. To disable set zero (default)
 * M92  - Set planner.axis_steps_per_mm - same syntax as G92
 * M104 - Set extruder target temp
 * M105 - Read current temp
 * M106 - Fan on
 * M107 - Fan off
 * M108 - Stop the waiting for heaters in M109, M190, M303. Does not affect the target temperature.
 * M109 - Sxxx Wait for extruder current temp to reach target temp. Waits only when heating
 *        Rxxx Wait for extruder current temp to reach target temp. Waits when heating and cooling
 *        IF AUTOTEMP is enabled, S<mintemp> B<maxtemp> F<factor>. Exit autotemp by any M109 without F
 * M110 - Set the current line number
 * M111 - Set debug flags with S<mask>. See flag bits defined in enum.h.
 * M112 - Emergency stop
 * M113 - Get or set the timeout interval for Host Keepalive "busy" messages
 * M114 - Output current position to serial port
 * M115 - Capabilities string
 * M117 - Display a message on the controller screen
 * M119 - Output Endstop status to serial port
 * M120 - Enable endstop detection
 * M121 - Disable endstop detection
 * M126 - Solenoid Air Valve Open (BariCUDA support by jmil)
 * M127 - Solenoid Air Valve Closed (BariCUDA vent to atmospheric pressure by jmil)
 * M128 - EtoP Open (BariCUDA EtoP = electricity to air pressure transducer by jmil)
 * M129 - EtoP Closed (BariCUDA EtoP = electricity to air pressure transducer by jmil)
 * M140 - Set bed target temp
 * M145 - Set the heatup state H<hotend> B<bed> F<fan speed> for S<material> (0=PLA, 1=ABS)
 * M149 - Set temperature units
 * M150 - Set BlinkM Color Output R: Red<0-255> U(!): Green<0-255> B: Blue<0-255> over i2c, G for green does not work.
 * M163 - Set a single proportion for a mixing extruder. Requires MIXING_EXTRUDER.
 * M164 - Save the mix as a virtual extruder. Requires MIXING_EXTRUDER and MIXING_VIRTUAL_TOOLS.
 * M165 - Set the proportions for a mixing extruder. Use parameters ABCDHI to set the mixing factors. Requires MIXING_EXTRUDER.
 * M190 - Sxxx Wait for bed current temp to reach target temp. Waits only when heating
 *        Rxxx Wait for bed current temp to reach target temp. Waits when heating and cooling
 * M200 - Set filament diameter, D<diameter>, setting E axis units to cubic. (Use S0 to revert to linear units.)
 * M201 - Set max acceleration in units/s^2 for print moves (M201 X1000 Y1000)
 * M202 - Set max acceleration in units/s^2 for travel moves (M202 X1000 Y1000) Unused in Marlin!!
 * M203 - Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in units/sec
 * M204 - Set default acceleration: P for Printing moves, R for Retract only (no X, Y, Z) moves and T for Travel (non printing) moves (ex. M204 P800 T3000 R9000) in units/sec^2
 * M205 - Set advanced settings. Current units apply:
            S<print> T<travel> minimum speeds
            B<minimum segment time>
            X<max xy jerk>, Z<max Z jerk>, E<max E jerk>
 * M206 - Set additional homing offset
 * M207 - Set Retract Length: S<length>, Feedrate: F<units/min>, and Z lift: Z<distance>
 * M208 - Set Recover (unretract) Additional (!) Length: S<length> and Feedrate: F<units/min>
 * M209 - Turn Automatic Retract Detection on/off: S<bool> (For slicers that don't support G10/11).
          Every normal extrude-only move will be classified as retract depending on the direction.
 * M211 - Enable, Disable, and/or Report software endstops: [S<bool>]
 * M218 - Set a tool offset: T<index> X<offset> Y<offset>
 * M220 - Set Feedrate Percentage: S<percent> ("FR" on your LCD)
 * M221 - Set Flow Percentage: S<percent>
 * M226 - Wait until the specified pin reaches the state required: P<pin number> S<pin state>
 * M240 - Trigger a camera to take a photograph
 * M250 - Set LCD contrast C<contrast value> (value 0..63)
 * M280 - Set servo position absolute. P: servo index, S: angle or microseconds
 * M300 - Play beep sound S<frequency Hz> P<duration ms>
 * M301 - Set PID parameters P I and D
 * M302 - Allow cold extrudes, or set the minimum extrude S<temperature>.
 * M303 - PID relay autotune S<temperature> sets the target temperature. (default target temperature = 150C)
 * M304 - Set bed PID parameters P I and D
 * M380 - Activate solenoid on active extruder
 * M381 - Disable all solenoids
 * M400 - Finish all moves
 * M401 - Lower Z probe if present
 * M402 - Raise Z probe if present
 * M404 - Display or set the Nominal Filament Width: [ N<diameter> ]
 * M405 - Enable Filament Sensor extrusion control. Optional delay between sensor and extruder: D<cm>
 * M406 - Disable Filament Sensor extrusion control
 * M407 - Display measured filament diameter in millimeters
 * M410 - Quickstop. Abort all the planned moves
 * M420 - Enable/Disable Mesh Leveling (with current values) S1=enable S0=disable
 * M421 - Set a single Z coordinate in the Mesh Leveling grid. X<units> Y<units> Z<units>
 * M428 - Set the home_offset logically based on the current_position
 * M500 - Store parameters in EEPROM
 * M501 - Read parameters from EEPROM (if you need reset them after you changed them temporarily).
 * M502 - Revert to the default "factory settings". You still need to store them in EEPROM afterwards if you want to.
 * M503 - Print the current settings (from memory not from EEPROM). Use S0 to leave off headings.
 * M540 - Use S[0|1] to enable or disable the stop SD card print on endstop hit (requires ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
 * M600 - Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
 * M665 - Set delta configurations: L<diagonal rod> R<delta radius> S<segments/s>
 * M666 - Set delta endstop adjustment
 * M605 - Set dual x-carriage movement mode: S<mode> [ X<duplication x-offset> R<duplication temp offset> ]
 * M851 - Set Z probe's Z offset in current units. (Negative values apply to probes that extend below the nozzle.)
 * M907 - Set digital trimpot motor current using axis codes.
 * M908 - Control digital trimpot directly.
 * M909 - DAC_STEPPER_CURRENT: Print digipot/DAC current value
 * M910 - DAC_STEPPER_CURRENT: Commit digipot/DAC value to external EEPROM via I2C
 * M350 - Set microstepping mode.
 * M351 - Toggle MS1 MS2 pins directly.
 *
 * ************ SCARA Specific - This can change to suit future G-code regulations
 * M360 - SCARA calibration: Move to cal-position ThetaA (0 deg calibration)
 * M361 - SCARA calibration: Move to cal-position ThetaB (90 deg calibration - steps per degree)
 * M362 - SCARA calibration: Move to cal-position PsiA (0 deg calibration)
 * M363 - SCARA calibration: Move to cal-position PsiB (90 deg calibration - steps per degree)
 * M364 - SCARA calibration: Move to cal-position PSIC (90 deg to Theta calibration position)
 * ************* SCARA End ***************
 *
 * ************ Custom codes - This can change to suit future G-code regulations
 * M100 - Watch Free Memory (For Debugging Only)
 * M928 - Start SD logging (M928 filename.g) - ended by M29
 * M999 - Restart after being stopped by error
 *
 * "T" Codes
 *
 * T0-T3 - Select a tool by index (usually an extruder) [ F<units/min> ]
 *
 */

#if ENABLED(M100_FREE_MEMORY_WATCHER)
  void gcode_M100();
#endif

#if ENABLED(SDSUPPORT)
  CardReader card;
#endif

#if ENABLED(EXPERIMENTAL_I2CBUS)
  TWIBus i2c;
#endif

bool Running = true;

uint8_t marlin_debug_flags = DEBUG_NONE;

float current_position[NUM_AXIS] = { 0.0 };
static float destination[NUM_AXIS] = { 0.0 };
bool axis_known_position[XYZ] = { false };
bool axis_homed[XYZ] = { false };

static long gcode_N, gcode_LastN, Stopped_gcode_LastN = 0;

static char command_queue[BUFSIZE][MAX_CMD_SIZE];
static char* current_command, *current_command_args;
static uint8_t cmd_queue_index_r = 0,
               cmd_queue_index_w = 0,
               commands_in_queue = 0;

#if ENABLED(INCH_MODE_SUPPORT)
  float linear_unit_factor = 1.0;
  float volumetric_unit_factor = 1.0;
#endif
#if ENABLED(TEMPERATURE_UNITS_SUPPORT)
  TempUnit input_temp_units = TEMPUNIT_C;
#endif

/**
 * Feed rates are often configured with mm/m
 * but the planner and stepper like mm/s units.
 */
float constexpr homing_feedrate_mm_s[] = {
  #if ENABLED(DELTA)
    MMM_TO_MMS(HOMING_FEEDRATE_Z), MMM_TO_MMS(HOMING_FEEDRATE_Z),
  #else
    MMM_TO_MMS(HOMING_FEEDRATE_XY), MMM_TO_MMS(HOMING_FEEDRATE_XY),
  #endif
  MMM_TO_MMS(HOMING_FEEDRATE_Z), 0
};
static float feedrate_mm_s = MMM_TO_MMS(1500.0), saved_feedrate_mm_s;
int feedrate_percentage = 100, saved_feedrate_percentage;

bool axis_relative_modes[] = AXIS_RELATIVE_MODES;
int flow_percentage[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(100);
bool volumetric_enabled = false;
float filament_size[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(DEFAULT_NOMINAL_FILAMENT_DIA);
float volumetric_multiplier[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(1.0);

// The distance that XYZ has been offset by G92. Reset by G28.
float position_shift[XYZ] = { 0 };

// This offset is added to the configured home position.
// Set by M206, M428, or menu item. Saved to EEPROM.
float home_offset[XYZ] = { 0 };

// Software Endstops are based on the configured limits.
#if ENABLED(min_software_endstops) || ENABLED(max_software_endstops)
  bool soft_endstops_enabled = true;
#endif
float soft_endstop_min[XYZ] = { X_MIN_POS, Y_MIN_POS, Z_MIN_POS },
      soft_endstop_max[XYZ] = { X_MAX_POS, Y_MAX_POS, Z_MAX_POS };

#if FAN_COUNT > 0
  int fanSpeeds[FAN_COUNT] = { 0 };
#endif

// The active extruder (tool). Set with T<extruder> command.
uint8_t active_extruder = 0;

// Relative Mode. Enable with G91, disable with G90.
static bool relative_mode = false;

volatile bool wait_for_heatup = true;

#if ENABLED(EMERGENCY_PARSER) && DISABLED(ULTIPANEL)
  volatile bool wait_for_user = false;
#endif

const char errormagic[] PROGMEM = "Error:";
const char echomagic[] PROGMEM = "echo:";
const char axis_codes[NUM_AXIS] = {'X', 'Y', 'Z', 'E'};

static int serial_count = 0;

// GCode parameter pointer used by code_seen(), code_value_float(), etc.
static char* seen_pointer;

// Next Immediate GCode Command pointer. NULL if none.
const char* queued_commands_P = NULL;

const int sensitive_pins[] = SENSITIVE_PINS; ///< Sensitive pin list for M42

// Inactivity shutdown
millis_t previous_cmd_ms = 0;
static millis_t max_inactive_time = 0;
static millis_t stepper_inactive_time = (DEFAULT_STEPPER_DEACTIVE_TIME) * 1000UL;

// Print Job Timer
#if ENABLED(PRINTCOUNTER)
  PrintCounter print_job_timer = PrintCounter();
#else
  Stopwatch print_job_timer = Stopwatch();
#endif

// Buzzer - I2C on the LCD or a BEEPER_PIN
#if ENABLED(LCD_USE_I2C_BUZZER)
  #define BUZZ(d,f) lcd_buzz(d, f)
#elif HAS_BUZZER
  Buzzer buzzer;
  #define BUZZ(d,f) buzzer.tone(d, f)
#else
  #define BUZZ(d,f) NOOP
#endif

static uint8_t target_extruder;

#if HAS_BED_PROBE
  float zprobe_zoffset = Z_PROBE_OFFSET_FROM_EXTRUDER;
#endif

#define PLANNER_XY_FEEDRATE() (min(planner.max_feedrate_mm_s[X_AXIS], planner.max_feedrate_mm_s[Y_AXIS]))

#if ENABLED(AUTO_BED_LEVELING_FEATURE)
  float xy_probe_feedrate_mm_s = MMM_TO_MMS(XY_PROBE_SPEED);
  #define XY_PROBE_FEEDRATE_MM_S xy_probe_feedrate_mm_s
#elif defined(XY_PROBE_SPEED)
  #define XY_PROBE_FEEDRATE_MM_S MMM_TO_MMS(XY_PROBE_SPEED)
#else
  #define XY_PROBE_FEEDRATE_MM_S PLANNER_XY_FEEDRATE()
#endif

#if ENABLED(Z_DUAL_ENDSTOPS)
  float z_endstop_adj = 0;
#endif

// Extruder offsets
#if HOTENDS > 1
  float hotend_offset[][HOTENDS] = {
    HOTEND_OFFSET_X,
    HOTEND_OFFSET_Y
    #ifdef HOTEND_OFFSET_Z
      , HOTEND_OFFSET_Z
    #endif
  };
#endif

#if HAS_Z_SERVO_ENDSTOP
  const int z_servo_angle[2] = Z_SERVO_ANGLES;
#endif

#if ENABLED(BARICUDA)
  int baricuda_valve_pressure = 0;
  int baricuda_e_to_p_pressure = 0;
#endif

#if ENABLED(FWRETRACT)

  bool autoretract_enabled = false;
  bool retracted[EXTRUDERS] = { false };
  bool retracted_swap[EXTRUDERS] = { false };

  float retract_length = RETRACT_LENGTH;
  float retract_length_swap = RETRACT_LENGTH_SWAP;
  float retract_feedrate_mm_s = RETRACT_FEEDRATE;
  float retract_zlift = RETRACT_ZLIFT;
  float retract_recover_length = RETRACT_RECOVER_LENGTH;
  float retract_recover_length_swap = RETRACT_RECOVER_LENGTH_SWAP;
  float retract_recover_feedrate_mm_s = RETRACT_RECOVER_FEEDRATE;

#endif // FWRETRACT

#if ENABLED(ULTIPANEL) && HAS_POWER_SWITCH
  bool powersupply =
    #if ENABLED(PS_DEFAULT_OFF)
      false
    #else
      true
    #endif
  ;
#endif

#if ENABLED(DELTA)

  #define SIN_60 0.8660254037844386
  #define COS_60 0.5

  float delta[ABC],
        endstop_adj[ABC] = { 0 };

  // these are the default values, can be overriden with M665
  float delta_radius = DELTA_RADIUS,
        delta_tower1_x = -SIN_60 * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1), // front left tower
        delta_tower1_y = -COS_60 * (delta_radius + DELTA_RADIUS_TRIM_TOWER_1),
        delta_tower2_x =  SIN_60 * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2), // front right tower
        delta_tower2_y = -COS_60 * (delta_radius + DELTA_RADIUS_TRIM_TOWER_2),
        delta_tower3_x = 0,                                                    // back middle tower
        delta_tower3_y = (delta_radius + DELTA_RADIUS_TRIM_TOWER_3),
        delta_diagonal_rod = DELTA_DIAGONAL_ROD,
        delta_diagonal_rod_trim_tower_1 = DELTA_DIAGONAL_ROD_TRIM_TOWER_1,
        delta_diagonal_rod_trim_tower_2 = DELTA_DIAGONAL_ROD_TRIM_TOWER_2,
        delta_diagonal_rod_trim_tower_3 = DELTA_DIAGONAL_ROD_TRIM_TOWER_3,
        delta_diagonal_rod_2_tower_1 = sq(delta_diagonal_rod + delta_diagonal_rod_trim_tower_1),
        delta_diagonal_rod_2_tower_2 = sq(delta_diagonal_rod + delta_diagonal_rod_trim_tower_2),
        delta_diagonal_rod_2_tower_3 = sq(delta_diagonal_rod + delta_diagonal_rod_trim_tower_3),
        delta_segments_per_second = DELTA_SEGMENTS_PER_SECOND,
        delta_clip_start_height = Z_MAX_POS;

  float delta_safe_distance_from_top();

#else

  static bool home_all_axis = true;

#endif

#if ENABLED(AUTO_BED_LEVELING_NONLINEAR)
  int nonlinear_grid_spacing[2] = { 0 };
  float bed_level_grid[ABL_GRID_POINTS_X][ABL_GRID_POINTS_Y];
#endif

#if IS_SCARA
  // Float constants for SCARA calculations
  const float L1 = SCARA_LINKAGE_1, L2 = SCARA_LINKAGE_2,
              L1_2 = sq(float(L1)), L1_2_2 = 2.0 * L1_2,
              L2_2 = sq(float(L2));

  float delta_segments_per_second = SCARA_SEGMENTS_PER_SECOND,
        delta[ABC];
#endif

float cartes[XYZ] = { 0 };

#if ENABLED(FILAMENT_WIDTH_SENSOR)
  bool filament_sensor = false;  //M405 turns on filament_sensor control, M406 turns it off
  float filament_width_nominal = DEFAULT_NOMINAL_FILAMENT_DIA,  // Nominal filament width. Change with M404
        filament_width_meas = DEFAULT_MEASURED_FILAMENT_DIA;    // Measured filament diameter
  int8_t measurement_delay[MAX_MEASUREMENT_DELAY + 1]; // Ring buffer to delayed measurement. Store extruder factor after subtracting 100
  int filwidth_delay_index[2] = { 0, -1 };  // Indexes into ring buffer
  int meas_delay_cm = MEASUREMENT_DELAY_CM;  //distance delay setting
#endif

#if ENABLED(FILAMENT_RUNOUT_SENSOR)
  static bool filament_ran_out = false;
#endif

#if ENABLED(FILAMENT_CHANGE_FEATURE)
  FilamentChangeMenuResponse filament_change_menu_response;
#endif

#if ENABLED(MIXING_EXTRUDER)
  float mixing_factor[MIXING_STEPPERS];
  #if MIXING_VIRTUAL_TOOLS > 1
    float mixing_virtual_tool_mix[MIXING_VIRTUAL_TOOLS][MIXING_STEPPERS];
  #endif
#endif

static bool send_ok[BUFSIZE];

#if HAS_SERVOS
  Servo servo[NUM_SERVOS];
  #define MOVE_SERVO(I, P) servo[I].move(P)
  #if HAS_Z_SERVO_ENDSTOP
    #define DEPLOY_Z_SERVO() MOVE_SERVO(Z_ENDSTOP_SERVO_NR, z_servo_angle[0])
    #define STOW_Z_SERVO() MOVE_SERVO(Z_ENDSTOP_SERVO_NR, z_servo_angle[1])
  #endif
#endif

#ifdef CHDK
  millis_t chdkHigh = 0;
  boolean chdkActive = false;
#endif

#if ENABLED(PID_EXTRUSION_SCALING)
  int lpq_len = 20;
#endif

#if ENABLED(HOST_KEEPALIVE_FEATURE)
  static MarlinBusyState busy_state = NOT_BUSY;
  static millis_t next_busy_signal_ms = 0;
  uint8_t host_keepalive_interval = DEFAULT_KEEPALIVE_INTERVAL;
  #define KEEPALIVE_STATE(n) do{ busy_state = n; }while(0)
#else
  #define host_keepalive() ;
  #define KEEPALIVE_STATE(n) ;
#endif // HOST_KEEPALIVE_FEATURE

#define DEFINE_PGM_READ_ANY(type, reader)       \
  static inline type pgm_read_any(const type *p)  \
  { return pgm_read_##reader##_near(p); }

DEFINE_PGM_READ_ANY(float,       float);
DEFINE_PGM_READ_ANY(signed char, byte);

#define XYZ_CONSTS_FROM_CONFIG(type, array, CONFIG) \
  static const PROGMEM type array##_P[XYZ] =        \
      { X_##CONFIG, Y_##CONFIG, Z_##CONFIG };     \
  static inline type array(int axis)          \
  { return pgm_read_any(&array##_P[axis]); }

XYZ_CONSTS_FROM_CONFIG(float, base_min_pos,   MIN_POS);
XYZ_CONSTS_FROM_CONFIG(float, base_max_pos,   MAX_POS);
XYZ_CONSTS_FROM_CONFIG(float, base_home_pos,  HOME_POS);
XYZ_CONSTS_FROM_CONFIG(float, max_length,     MAX_LENGTH);
XYZ_CONSTS_FROM_CONFIG(float, home_bump_mm,   HOME_BUMP_MM);
XYZ_CONSTS_FROM_CONFIG(signed char, home_dir, HOME_DIR);

/**
 * ***************************************************************************
 * ******************************** FUNCTIONS ********************************
 * ***************************************************************************
 */

void stop();

void get_available_commands();
void process_next_command();
void prepare_move_to_destination();

void get_cartesian_from_steppers();
void set_current_from_steppers_for_axis(const AxisEnum axis);

#if ENABLED(ARC_SUPPORT)
  void plan_arc(float target[NUM_AXIS], float* offset, uint8_t clockwise);
#endif

#if ENABLED(BEZIER_CURVE_SUPPORT)
  void plan_cubic_move(const float offset[4]);
#endif

void serial_echopair_P(const char* s_P, const char *v)   { serialprintPGM(s_P); SERIAL_ECHO(v); }
void serial_echopair_P(const char* s_P, char v)          { serialprintPGM(s_P); SERIAL_CHAR(v); }
void serial_echopair_P(const char* s_P, int v)           { serialprintPGM(s_P); SERIAL_ECHO(v); }
void serial_echopair_P(const char* s_P, long v)          { serialprintPGM(s_P); SERIAL_ECHO(v); }
void serial_echopair_P(const char* s_P, float v)         { serialprintPGM(s_P); SERIAL_ECHO(v); }
void serial_echopair_P(const char* s_P, double v)        { serialprintPGM(s_P); SERIAL_ECHO(v); }
void serial_echopair_P(const char* s_P, unsigned long v) { serialprintPGM(s_P); SERIAL_ECHO(v); }

void tool_change(const uint8_t tmp_extruder, const float fr_mm_s=0.0, bool no_move=false);
static void report_current_position();

#if ENABLED(DEBUG_LEVELING_FEATURE)
  void print_xyz(const char* prefix, const char* suffix, const float x, const float y, const float z) {
    serialprintPGM(prefix);
    SERIAL_ECHOPAIR("(", x);
    SERIAL_ECHOPAIR(", ", y);
    SERIAL_ECHOPAIR(", ", z);
    SERIAL_ECHOPGM(")");

    if (suffix) serialprintPGM(suffix);
    else SERIAL_EOL;
  }

  void print_xyz(const char* prefix, const char* suffix, const float xyz[]) {
    print_xyz(prefix, suffix, xyz[X_AXIS], xyz[Y_AXIS], xyz[Z_AXIS]);
  }

  #if ENABLED(AUTO_BED_LEVELING_FEATURE)
    void print_xyz(const char* prefix, const char* suffix, const vector_3 &xyz) {
      print_xyz(prefix, suffix, xyz.x, xyz.y, xyz.z);
    }
  #endif

  #define DEBUG_POS(SUFFIX,VAR) do { \
    print_xyz(PSTR(STRINGIFY(VAR) "="), PSTR(" : " SUFFIX "\n"), VAR); } while(0)
#endif

/**
 * sync_plan_position
 *
 * Set the planner/stepper positions directly from current_position with
 * no kinematic translation. Used for homing axes and cartesian/core syncing.
 */
inline void sync_plan_position() {
  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) DEBUG_POS("sync_plan_position", current_position);
  #endif
  planner.set_position_mm(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS]);
}
inline void sync_plan_position_e() { planner.set_e_position_mm(current_position[E_AXIS]); }

#if IS_KINEMATIC

  inline void sync_plan_position_kinematic() {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("sync_plan_position_kinematic", current_position);
    #endif
    inverse_kinematics(current_position);
    planner.set_position_mm(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], current_position[E_AXIS]);
  }
  #define SYNC_PLAN_POSITION_KINEMATIC() sync_plan_position_kinematic()

#else

  #define SYNC_PLAN_POSITION_KINEMATIC() sync_plan_position()

#endif

#if ENABLED(SDSUPPORT)
  #include "SdFatUtil.h"
  int freeMemory() { return SdFatUtil::FreeRam(); }
#else
extern "C" {
  extern unsigned int __bss_end;
  extern unsigned int __heap_start;
  extern void* __brkval;

  int freeMemory() {
    int free_memory;
    if ((int)__brkval == 0)
      free_memory = ((int)&free_memory) - ((int)&__bss_end);
    else
      free_memory = ((int)&free_memory) - ((int)__brkval);
    return free_memory;
  }
}
#endif //!SDSUPPORT

#if ENABLED(DIGIPOT_I2C)
  extern void digipot_i2c_set_current(int channel, float current);
  extern void digipot_i2c_init();
#endif

/**
 * Inject the next "immediate" command, when possible.
 * Return true if any immediate commands remain to inject.
 */
static bool drain_queued_commands_P() {
  if (queued_commands_P != NULL) {
    size_t i = 0;
    char c, cmd[30];
    strncpy_P(cmd, queued_commands_P, sizeof(cmd) - 1);
    cmd[sizeof(cmd) - 1] = '\0';
    while ((c = cmd[i]) && c != '\n') i++; // find the end of this gcode command
    cmd[i] = '\0';
    if (enqueue_and_echo_command(cmd)) {   // success?
      if (c)                               // newline char?
        queued_commands_P += i + 1;        // advance to the next command
      else
        queued_commands_P = NULL;          // nul char? no more commands
    }
  }
  return (queued_commands_P != NULL);      // return whether any more remain
}

/**
 * Record one or many commands to run from program memory.
 * Aborts the current queue, if any.
 * Note: drain_queued_commands_P() must be called repeatedly to drain the commands afterwards
 */
void enqueue_and_echo_commands_P(const char* pgcode) {
  queued_commands_P = pgcode;
  drain_queued_commands_P(); // first command executed asap (when possible)
}

void clear_command_queue() {
  cmd_queue_index_r = cmd_queue_index_w;
  commands_in_queue = 0;
}

/**
 * Once a new command is in the ring buffer, call this to commit it
 */
inline void _commit_command(bool say_ok) {
  send_ok[cmd_queue_index_w] = say_ok;
  cmd_queue_index_w = (cmd_queue_index_w + 1) % BUFSIZE;
  commands_in_queue++;
}

/**
 * Copy a command directly into the main command buffer, from RAM.
 * Returns true if successfully adds the command
 */
inline bool _enqueuecommand(const char* cmd, bool say_ok=false) {
  if (*cmd == ';' || commands_in_queue >= BUFSIZE) return false;
  strcpy(command_queue[cmd_queue_index_w], cmd);
  _commit_command(say_ok);
  return true;
}

void enqueue_and_echo_command_now(const char* cmd) {
  while (!enqueue_and_echo_command(cmd)) idle();
}

/**
 * Enqueue with Serial Echo
 */
bool enqueue_and_echo_command(const char* cmd, bool say_ok/*=false*/) {
  if (_enqueuecommand(cmd, say_ok)) {
    SERIAL_ECHO_START;
    SERIAL_ECHOPAIR(MSG_Enqueueing, cmd);
    SERIAL_ECHOLNPGM("\"");
    return true;
  }
  return false;
}

void setup_killpin() {
  #if HAS_KILL
    SET_INPUT(KILL_PIN);
    WRITE(KILL_PIN, HIGH);
  #endif
}

#if ENABLED(FILAMENT_RUNOUT_SENSOR)

  void setup_filrunoutpin() {
    pinMode(FIL_RUNOUT_PIN, INPUT);
    #if ENABLED(ENDSTOPPULLUP_FIL_RUNOUT)
      WRITE(FIL_RUNOUT_PIN, HIGH);
    #endif
  }

#endif

// Set home pin
void setup_homepin(void) {
  #if HAS_HOME
    SET_INPUT(HOME_PIN);
    WRITE(HOME_PIN, HIGH);
  #endif
}

void setup_photpin() {
  #if HAS_PHOTOGRAPH
    OUT_WRITE(PHOTOGRAPH_PIN, LOW);
  #endif
}

void setup_powerhold() {
  #if HAS_SUICIDE
    OUT_WRITE(SUICIDE_PIN, HIGH);
  #endif
  #if HAS_POWER_SWITCH
    #if ENABLED(PS_DEFAULT_OFF)
      OUT_WRITE(PS_ON_PIN, PS_ON_ASLEEP);
    #else
      OUT_WRITE(PS_ON_PIN, PS_ON_AWAKE);
    #endif
  #endif
}

void suicide() {
  #if HAS_SUICIDE
    OUT_WRITE(SUICIDE_PIN, LOW);
  #endif
}

void servo_init() {
  #if NUM_SERVOS >= 1 && HAS_SERVO_0
    servo[0].attach(SERVO0_PIN);
    servo[0].detach(); // Just set up the pin. We don't have a position yet. Don't move to a random position.
  #endif
  #if NUM_SERVOS >= 2 && HAS_SERVO_1
    servo[1].attach(SERVO1_PIN);
    servo[1].detach();
  #endif
  #if NUM_SERVOS >= 3 && HAS_SERVO_2
    servo[2].attach(SERVO2_PIN);
    servo[2].detach();
  #endif
  #if NUM_SERVOS >= 4 && HAS_SERVO_3
    servo[3].attach(SERVO3_PIN);
    servo[3].detach();
  #endif

  #if HAS_Z_SERVO_ENDSTOP
    /**
     * Set position of Z Servo Endstop
     *
     * The servo might be deployed and positioned too low to stow
     * when starting up the machine or rebooting the board.
     * There's no way to know where the nozzle is positioned until
     * homing has been done - no homing with z-probe without init!
     *
     */
    STOW_Z_SERVO();
  #endif
}

/**
 * Stepper Reset (RigidBoard, et.al.)
 */
#if HAS_STEPPER_RESET
  void disableStepperDrivers() {
    pinMode(STEPPER_RESET_PIN, OUTPUT);
    digitalWrite(STEPPER_RESET_PIN, LOW);  // drive it down to hold in reset motor driver chips
  }
  void enableStepperDrivers() { pinMode(STEPPER_RESET_PIN, INPUT); }  // set to input, which allows it to be pulled high by pullups
#endif

#if ENABLED(EXPERIMENTAL_I2CBUS) && I2C_SLAVE_ADDRESS > 0

  void i2c_on_receive(int bytes) { // just echo all bytes received to serial
    i2c.receive(bytes);
  }

  void i2c_on_request() {          // just send dummy data for now
    i2c.reply("Hello World!\n");
  }

#endif

void gcode_line_error(const char* err, bool doFlush = true) {
  SERIAL_ERROR_START;
  serialprintPGM(err);
  SERIAL_ERRORLN(gcode_LastN);
  //Serial.println(gcode_N);
  if (doFlush) FlushSerialRequestResend();
  serial_count = 0;
}

inline void get_serial_commands() {
  static char serial_line_buffer[MAX_CMD_SIZE];
  static boolean serial_comment_mode = false;

  // If the command buffer is empty for too long,
  // send "wait" to indicate Marlin is still waiting.
  #if defined(NO_TIMEOUTS) && NO_TIMEOUTS > 0
    static millis_t last_command_time = 0;
    millis_t ms = millis();
    if (commands_in_queue == 0 && !MYSERIAL.available() && ELAPSED(ms, last_command_time + NO_TIMEOUTS)) {
      SERIAL_ECHOLNPGM(MSG_WAIT);
      last_command_time = ms;
    }
  #endif

  /**
   * Loop while serial characters are incoming and the queue is not full
   */
  while (commands_in_queue < BUFSIZE && MYSERIAL.available() > 0) {

    char serial_char = MYSERIAL.read();

    /**
     * If the character ends the line
     */
    if (serial_char == '\n' || serial_char == '\r') {

      serial_comment_mode = false; // end of line == end of comment

      if (!serial_count) continue; // skip empty lines

      serial_line_buffer[serial_count] = 0; // terminate string
      serial_count = 0; //reset buffer

      char* command = serial_line_buffer;

      while (*command == ' ') command++; // skip any leading spaces
      char* npos = (*command == 'N') ? command : NULL; // Require the N parameter to start the line
      char* apos = strchr(command, '*');

      if (npos) {

        boolean M110 = strstr_P(command, PSTR("M110")) != NULL;

        if (M110) {
          char* n2pos = strchr(command + 4, 'N');
          if (n2pos) npos = n2pos;
        }

        gcode_N = strtol(npos + 1, NULL, 10);

        if (gcode_N != gcode_LastN + 1 && !M110) {
          gcode_line_error(PSTR(MSG_ERR_LINE_NO));
          return;
        }

        if (apos) {
          byte checksum = 0, count = 0;
          while (command[count] != '*') checksum ^= command[count++];

          if (strtol(apos + 1, NULL, 10) != checksum) {
            gcode_line_error(PSTR(MSG_ERR_CHECKSUM_MISMATCH));
            return;
          }
          // if no errors, continue parsing
        }
        else {
          gcode_line_error(PSTR(MSG_ERR_NO_CHECKSUM));
          return;
        }

        gcode_LastN = gcode_N;
        // if no errors, continue parsing
      }
      else if (apos) { // No '*' without 'N'
        gcode_line_error(PSTR(MSG_ERR_NO_LINENUMBER_WITH_CHECKSUM), false);
        return;
      }

      // Movement commands alert when stopped
      if (IsStopped()) {
        char* gpos = strchr(command, 'G');
        if (gpos) {
          int codenum = strtol(gpos + 1, NULL, 10);
          switch (codenum) {
            case 0:
            case 1:
            case 2:
            case 3:
              SERIAL_ERRORLNPGM(MSG_ERR_STOPPED);
              LCD_MESSAGEPGM(MSG_STOPPED);
              break;
          }
        }
      }

      #if DISABLED(EMERGENCY_PARSER)
        // If command was e-stop process now
        if (strcmp(command, "M108") == 0) wait_for_heatup = false;
        if (strcmp(command, "M112") == 0) kill(PSTR(MSG_KILLED));
        if (strcmp(command, "M410") == 0) { quickstop_stepper(); }
      #endif

      #if defined(NO_TIMEOUTS) && NO_TIMEOUTS > 0
        last_command_time = ms;
      #endif

      // Add the command to the queue
      _enqueuecommand(serial_line_buffer, true);
    }
    else if (serial_count >= MAX_CMD_SIZE - 1) {
      // Keep fetching, but ignore normal characters beyond the max length
      // The command will be injected when EOL is reached
    }
    else if (serial_char == '\\') {  // Handle escapes
      if (MYSERIAL.available() > 0) {
        // if we have one more character, copy it over
        serial_char = MYSERIAL.read();
        if (!serial_comment_mode) serial_line_buffer[serial_count++] = serial_char;
      }
      // otherwise do nothing
    }
    else { // it's not a newline, carriage return or escape char
      if (serial_char == ';') serial_comment_mode = true;
      if (!serial_comment_mode) serial_line_buffer[serial_count++] = serial_char;
    }

  } // queue has space, serial has data
}

#if ENABLED(SDSUPPORT)

  inline void get_sdcard_commands() {
    static bool stop_buffering = false,
                sd_comment_mode = false;

    if (!card.sdprinting) return;

    /**
     * '#' stops reading from SD to the buffer prematurely, so procedural
     * macro calls are possible. If it occurs, stop_buffering is triggered
     * and the buffer is run dry; this character _can_ occur in serial com
     * due to checksums, however, no checksums are used in SD printing.
     */

    if (commands_in_queue == 0) stop_buffering = false;

    uint16_t sd_count = 0;
    bool card_eof = card.eof();
    while (commands_in_queue < BUFSIZE && !card_eof && !stop_buffering) {
      int16_t n = card.get();
      char sd_char = (char)n;
      card_eof = card.eof();
      if (card_eof || n == -1
          || sd_char == '\n' || sd_char == '\r'
          || ((sd_char == '#' || sd_char == ':') && !sd_comment_mode)
      ) {
        if (card_eof) {
          SERIAL_PROTOCOLLNPGM(MSG_FILE_PRINTED);
          card.printingHasFinished();
          card.checkautostart(true);
        }
        else if (n == -1) {
          SERIAL_ERROR_START;
          SERIAL_ECHOLNPGM(MSG_SD_ERR_READ);
        }
        if (sd_char == '#') stop_buffering = true;

        sd_comment_mode = false; //for new command

        if (!sd_count) continue; //skip empty lines

        command_queue[cmd_queue_index_w][sd_count] = '\0'; //terminate string
        sd_count = 0; //clear buffer

        _commit_command(false);
      }
      else if (sd_count >= MAX_CMD_SIZE - 1) {
        /**
         * Keep fetching, but ignore normal characters beyond the max length
         * The command will be injected when EOL is reached
         */
      }
      else {
        if (sd_char == ';') sd_comment_mode = true;
        if (!sd_comment_mode) command_queue[cmd_queue_index_w][sd_count++] = sd_char;
      }
    }
  }

#endif // SDSUPPORT

/**
 * Add to the circular command queue the next command from:
 *  - The command-injection queue (queued_commands_P)
 *  - The active serial input (usually USB)
 *  - The SD card file being actively printed
 */
void get_available_commands() {

  // if any immediate commands remain, don't get other commands yet
  if (drain_queued_commands_P()) return;

  get_serial_commands();

  #if ENABLED(SDSUPPORT)
    get_sdcard_commands();
  #endif
}

inline bool code_has_value() {
  int i = 1;
  char c = seen_pointer[i];
  while (c == ' ') c = seen_pointer[++i];
  if (c == '-' || c == '+') c = seen_pointer[++i];
  if (c == '.') c = seen_pointer[++i];
  return NUMERIC(c);
}

inline float code_value_float() {
  float ret;
  char* e = strchr(seen_pointer, 'E');
  if (e) {
    *e = 0;
    ret = strtod(seen_pointer + 1, NULL);
    *e = 'E';
  }
  else
    ret = strtod(seen_pointer + 1, NULL);
  return ret;
}

inline unsigned long code_value_ulong() { return strtoul(seen_pointer + 1, NULL, 10); }

inline long code_value_long() { return strtol(seen_pointer + 1, NULL, 10); }

inline int code_value_int() { return (int)strtol(seen_pointer + 1, NULL, 10); }

inline uint16_t code_value_ushort() { return (uint16_t)strtoul(seen_pointer + 1, NULL, 10); }

inline uint8_t code_value_byte() { return (uint8_t)(constrain(strtol(seen_pointer + 1, NULL, 10), 0, 255)); }

inline bool code_value_bool() { return !code_has_value() || code_value_byte() > 0; }

#if ENABLED(INCH_MODE_SUPPORT)
  inline void set_input_linear_units(LinearUnit units) {
    switch (units) {
      case LINEARUNIT_INCH:
        linear_unit_factor = 25.4;
        break;
      case LINEARUNIT_MM:
      default:
        linear_unit_factor = 1.0;
        break;
    }
    volumetric_unit_factor = pow(linear_unit_factor, 3.0);
  }

  inline float axis_unit_factor(int axis) {
    return (axis == E_AXIS && volumetric_enabled ? volumetric_unit_factor : linear_unit_factor);
  }

  inline float code_value_linear_units() { return code_value_float() * linear_unit_factor; }
  inline float code_value_axis_units(int axis) { return code_value_float() * axis_unit_factor(axis); }
  inline float code_value_per_axis_unit(int axis) { return code_value_float() / axis_unit_factor(axis); }

#else

  inline float code_value_linear_units() { return code_value_float(); }
  inline float code_value_axis_units(int axis) { UNUSED(axis); return code_value_float(); }
  inline float code_value_per_axis_unit(int axis) { UNUSED(axis); return code_value_float(); }

#endif

#if ENABLED(TEMPERATURE_UNITS_SUPPORT)
  inline void set_input_temp_units(TempUnit units) { input_temp_units = units; }

  float code_value_temp_abs() {
    switch (input_temp_units) {
      case TEMPUNIT_C:
        return code_value_float();
      case TEMPUNIT_F:
        return (code_value_float() - 32) * 0.5555555556;
      case TEMPUNIT_K:
        return code_value_float() - 272.15;
      default:
        return code_value_float();
    }
  }

  float code_value_temp_diff() {
    switch (input_temp_units) {
      case TEMPUNIT_C:
      case TEMPUNIT_K:
        return code_value_float();
      case TEMPUNIT_F:
        return code_value_float() * 0.5555555556;
      default:
        return code_value_float();
    }
  }
#else
  float code_value_temp_abs() { return code_value_float(); }
  float code_value_temp_diff() { return code_value_float(); }
#endif

FORCE_INLINE millis_t code_value_millis() { return code_value_ulong(); }
inline millis_t code_value_millis_from_seconds() { return code_value_float() * 1000; }

bool code_seen(char code) {
  seen_pointer = strchr(current_command_args, code);
  return (seen_pointer != NULL); // Return TRUE if the code-letter was found
}

/**
 * Set target_extruder from the T parameter or the active_extruder
 *
 * Returns TRUE if the target is invalid
 */
bool get_target_extruder_from_command(int code) {
  if (code_seen('T')) {
    if (code_value_byte() >= EXTRUDERS) {
      SERIAL_ECHO_START;
      SERIAL_CHAR('M');
      SERIAL_ECHO(code);
      SERIAL_ECHOLNPAIR(" " MSG_INVALID_EXTRUDER " ", code_value_byte());
      return true;
    }
    target_extruder = code_value_byte();
  }
  else
    target_extruder = active_extruder;

  return false;
}

#if ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
  bool extruder_duplication_enabled = false; // Used in Dual X mode 2
#endif

#if ENABLED(DUAL_X_CARRIAGE)

  #define DXC_FULL_CONTROL_MODE 0
  #define DXC_AUTO_PARK_MODE    1
  #define DXC_DUPLICATION_MODE  2

  static int dual_x_carriage_mode = DEFAULT_DUAL_X_CARRIAGE_MODE;

  static float x_home_pos(int extruder) {
    if (extruder == 0)
      return LOGICAL_X_POSITION(base_home_pos(X_AXIS));
    else
      /**
       * In dual carriage mode the extruder offset provides an override of the
       * second X-carriage offset when homed - otherwise X2_HOME_POS is used.
       * This allow soft recalibration of the second extruder offset position
       * without firmware reflash (through the M218 command).
       */
      return (hotend_offset[X_AXIS][1] > 0) ? hotend_offset[X_AXIS][1] : X2_HOME_POS;
  }

  static int x_home_dir(int extruder) {
    return (extruder == 0) ? X_HOME_DIR : X2_HOME_DIR;
  }

  static float inactive_extruder_x_pos = X2_MAX_POS; // used in mode 0 & 1
  static bool active_extruder_parked = false;        // used in mode 1 & 2
  static float raised_parked_position[NUM_AXIS];     // used in mode 1
  static millis_t delayed_move_time = 0;             // used in mode 1
  static float duplicate_extruder_x_offset = DEFAULT_DUPLICATION_X_OFFSET; // used in mode 2
  static float duplicate_extruder_temp_offset = 0;   // used in mode 2

#endif //DUAL_X_CARRIAGE

/**
 * Software endstops can be used to monitor the open end of
 * an axis that has a hardware endstop on the other end. Or
 * they can prevent axes from moving past endstops and grinding.
 *
 * To keep doing their job as the coordinate system changes,
 * the software endstop positions must be refreshed to remain
 * at the same positions relative to the machine.
 */
void update_software_endstops(AxisEnum axis) {
  float offs = LOGICAL_POSITION(0, axis);

  #if ENABLED(DUAL_X_CARRIAGE)
    if (axis == X_AXIS) {
      float dual_max_x = max(hotend_offset[X_AXIS][1], X2_MAX_POS);
      if (active_extruder != 0) {
        soft_endstop_min[X_AXIS] = X2_MIN_POS + offs;
        soft_endstop_max[X_AXIS] = dual_max_x + offs;
        return;
      }
      else if (dual_x_carriage_mode == DXC_DUPLICATION_MODE) {
        soft_endstop_min[X_AXIS] = base_min_pos(X_AXIS) + offs;
        soft_endstop_max[X_AXIS] = min(base_max_pos(X_AXIS), dual_max_x - duplicate_extruder_x_offset) + offs;
        return;
      }
    }
    else
  #endif
  {
    soft_endstop_min[axis] = base_min_pos(axis) + offs;
    soft_endstop_max[axis] = base_max_pos(axis) + offs;
  }

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOPAIR("For ", axis_codes[axis]);
      SERIAL_ECHOPAIR(" axis:\n home_offset = ", home_offset[axis]);
      SERIAL_ECHOPAIR("\n position_shift = ", position_shift[axis]);
      SERIAL_ECHOPAIR("\n soft_endstop_min = ", soft_endstop_min[axis]);
      SERIAL_ECHOLNPAIR("\n soft_endstop_max = ", soft_endstop_max[axis]);
    }
  #endif

  #if ENABLED(DELTA)
    if (axis == Z_AXIS)
      delta_clip_start_height = soft_endstop_max[axis] - delta_safe_distance_from_top();
  #endif

}

/**
 * Change the home offset for an axis, update the current
 * position and the software endstops to retain the same
 * relative distance to the new home.
 *
 * Since this changes the current_position, code should
 * call sync_plan_position soon after this.
 */
static void set_home_offset(AxisEnum axis, float v) {
  current_position[axis] += v - home_offset[axis];
  home_offset[axis] = v;
  update_software_endstops(axis);
}

/**
 * Set an axis' current position to its home position (after homing).
 *
 * For Core and Cartesian robots this applies one-to-one when an
 * individual axis has been homed.
 *
 * DELTA should wait until all homing is done before setting the XYZ
 * current_position to home, because homing is a single operation.
 * In the case where the axis positions are already known and previously
 * homed, DELTA could home to X or Y individually by moving either one
 * to the center. However, homing Z always homes XY and Z.
 *
 * SCARA should wait until all XY homing is done before setting the XY
 * current_position to home, because neither X nor Y is at home until
 * both are at home. Z can however be homed individually.
 * 
 */
static void set_axis_is_at_home(AxisEnum axis) {
  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOPAIR(">>> set_axis_is_at_home(", axis_codes[axis]);
      SERIAL_ECHOLNPGM(")");
    }
  #endif

  axis_known_position[axis] = axis_homed[axis] = true;

  position_shift[axis] = 0;
  update_software_endstops(axis);

  #if ENABLED(DUAL_X_CARRIAGE)
    if (axis == X_AXIS && (active_extruder != 0 || dual_x_carriage_mode == DXC_DUPLICATION_MODE)) {
      if (active_extruder != 0)
        current_position[X_AXIS] = x_home_pos(active_extruder);
      else
        current_position[X_AXIS] = LOGICAL_X_POSITION(base_home_pos(X_AXIS));
      update_software_endstops(X_AXIS);
      return;
    }
  #endif

  #if ENABLED(MORGAN_SCARA)

    /**
     * Morgan SCARA homes XY at the same time
     */
    if (axis == X_AXIS || axis == Y_AXIS) {

      float homeposition[XYZ];
      LOOP_XYZ(i) homeposition[i] = LOGICAL_POSITION(base_home_pos(i), i);

      // SERIAL_ECHOPAIR("homeposition X:", homeposition[X_AXIS]);
      // SERIAL_ECHOLNPAIR(" Y:", homeposition[Y_AXIS]);

      /**
       * Get Home position SCARA arm angles using inverse kinematics,
       * and calculate homing offset using forward kinematics
       */
      inverse_kinematics(homeposition);
      forward_kinematics_SCARA(delta[A_AXIS], delta[B_AXIS]);

      // SERIAL_ECHOPAIR("Cartesian X:", cartes[X_AXIS]);
      // SERIAL_ECHOLNPAIR(" Y:", cartes[Y_AXIS]);

      current_position[axis] = LOGICAL_POSITION(cartes[axis], axis);

      /**
       * SCARA home positions are based on configuration since the actual
       * limits are determined by the inverse kinematic transform.
       */
      soft_endstop_min[axis] = base_min_pos(axis); // + (cartes[axis] - base_home_pos(axis));
      soft_endstop_max[axis] = base_max_pos(axis); // + (cartes[axis] - base_home_pos(axis));
    }
    else
  #endif
  {
    current_position[axis] = LOGICAL_POSITION(base_home_pos(axis), axis);
  }

  /**
   * Z Probe Z Homing? Account for the probe's Z offset.
   */
  #if HAS_BED_PROBE && Z_HOME_DIR < 0
    if (axis == Z_AXIS) {
      #if HOMING_Z_WITH_PROBE

        current_position[Z_AXIS] -= zprobe_zoffset;

        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) {
            SERIAL_ECHOLNPGM("*** Z HOMED WITH PROBE (Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN) ***");
            SERIAL_ECHOLNPAIR("> zprobe_zoffset = ", zprobe_zoffset);
          }
        #endif

      #elif ENABLED(DEBUG_LEVELING_FEATURE)

        if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("*** Z HOMED TO ENDSTOP (Z_MIN_PROBE_ENDSTOP) ***");

      #endif
    }
  #endif

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOPAIR("> home_offset[", axis_codes[axis]);
      SERIAL_ECHOLNPAIR("] = ", home_offset[axis]);
      DEBUG_POS("", current_position);
      SERIAL_ECHOPAIR("<<< set_axis_is_at_home(", axis_codes[axis]);
      SERIAL_ECHOLNPGM(")");
    }
  #endif
}

/**
 * Some planner shorthand inline functions
 */
inline float get_homing_bump_feedrate(AxisEnum axis) {
  int constexpr homing_bump_divisor[] = HOMING_BUMP_DIVISOR;
  int hbd = homing_bump_divisor[axis];
  if (hbd < 1) {
    hbd = 10;
    SERIAL_ECHO_START;
    SERIAL_ECHOLNPGM("Warning: Homing Bump Divisor < 1");
  }
  return homing_feedrate_mm_s[axis] / hbd;
}

//
// line_to_current_position
// Move the planner to the current position from wherever it last moved
// (or from wherever it has been told it is located).
//
inline void line_to_current_position() {
  planner.buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], feedrate_mm_s, active_extruder);
}

//
// line_to_destination
// Move the planner, not necessarily synced with current_position
//
inline void line_to_destination(float fr_mm_s) {
  planner.buffer_line(destination[X_AXIS], destination[Y_AXIS], destination[Z_AXIS], destination[E_AXIS], fr_mm_s, active_extruder);
}
inline void line_to_destination() { line_to_destination(feedrate_mm_s); }

inline void set_current_to_destination() { memcpy(current_position, destination, sizeof(current_position)); }
inline void set_destination_to_current() { memcpy(destination, current_position, sizeof(destination)); }

#if IS_KINEMATIC
  /**
   * Calculate delta, start a line, and set current_position to destination
   */
  void prepare_uninterpolated_move_to_destination(const float fr_mm_s=0.0) {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("prepare_uninterpolated_move_to_destination", destination);
    #endif

    if ( current_position[X_AXIS] == destination[X_AXIS]
      && current_position[Y_AXIS] == destination[Y_AXIS]
      && current_position[Z_AXIS] == destination[Z_AXIS]
      && current_position[E_AXIS] == destination[E_AXIS]
    ) return;

    refresh_cmd_timeout();
    inverse_kinematics(destination);
    planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], destination[E_AXIS], MMS_SCALED(fr_mm_s ? fr_mm_s : feedrate_mm_s), active_extruder);
    set_current_to_destination();
  }
#endif // IS_KINEMATIC

/**
 *  Plan a move to (X, Y, Z) and set the current_position
 *  The final current_position may not be the one that was requested
 */
void do_blocking_move_to(const float &x, const float &y, const float &z, const float &fr_mm_s /*=0.0*/) {
  float old_feedrate_mm_s = feedrate_mm_s;

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) print_xyz(PSTR(">>> do_blocking_move_to"), NULL, x, y, z);
  #endif

  #if ENABLED(DELTA)

    feedrate_mm_s = fr_mm_s ? fr_mm_s : XY_PROBE_FEEDRATE_MM_S;

    set_destination_to_current();          // sync destination at the start

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("set_destination_to_current", destination);
    #endif

    // when in the danger zone
    if (current_position[Z_AXIS] > delta_clip_start_height) {
      if (z > delta_clip_start_height) {   // staying in the danger zone
        destination[X_AXIS] = x;           // move directly (uninterpolated)
        destination[Y_AXIS] = y;
        destination[Z_AXIS] = z;
        prepare_uninterpolated_move_to_destination(); // set_current_to_destination
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("danger zone move", current_position);
        #endif
        return;
      }
      else {
        destination[Z_AXIS] = delta_clip_start_height;
        prepare_uninterpolated_move_to_destination(); // set_current_to_destination
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("zone border move", current_position);
        #endif
      }
    }

    if (z > current_position[Z_AXIS]) {    // raising?
      destination[Z_AXIS] = z;
      prepare_uninterpolated_move_to_destination();   // set_current_to_destination
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) DEBUG_POS("z raise move", current_position);
      #endif
    }

    destination[X_AXIS] = x;
    destination[Y_AXIS] = y;
    prepare_move_to_destination();         // set_current_to_destination
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("xy move", current_position);
    #endif

    if (z < current_position[Z_AXIS]) {    // lowering?
      destination[Z_AXIS] = z;
      prepare_uninterpolated_move_to_destination();   // set_current_to_destination
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) DEBUG_POS("z lower move", current_position);
      #endif
    }

  #elif IS_SCARA

    set_destination_to_current();

    // If Z needs to raise, do it before moving XY
    if (destination[Z_AXIS] < z) {
      destination[Z_AXIS] = z;
      prepare_uninterpolated_move_to_destination(fr_mm_s ? fr_mm_s : homing_feedrate_mm_s[Z_AXIS]);
    }

    destination[X_AXIS] = x;
    destination[Y_AXIS] = y;
    prepare_uninterpolated_move_to_destination(fr_mm_s ? fr_mm_s : XY_PROBE_FEEDRATE_MM_S);

    // If Z needs to lower, do it after moving XY
    if (destination[Z_AXIS] > z) {
      destination[Z_AXIS] = z;
      prepare_uninterpolated_move_to_destination(fr_mm_s ? fr_mm_s : homing_feedrate_mm_s[Z_AXIS]);
    }

  #else

    // If Z needs to raise, do it before moving XY
    if (current_position[Z_AXIS] < z) {
      feedrate_mm_s = fr_mm_s ? fr_mm_s : homing_feedrate_mm_s[Z_AXIS];
      current_position[Z_AXIS] = z;
      line_to_current_position();
    }

    feedrate_mm_s = fr_mm_s ? fr_mm_s : XY_PROBE_FEEDRATE_MM_S;
    current_position[X_AXIS] = x;
    current_position[Y_AXIS] = y;
    line_to_current_position();

    // If Z needs to lower, do it after moving XY
    if (current_position[Z_AXIS] > z) {
      feedrate_mm_s = fr_mm_s ? fr_mm_s : homing_feedrate_mm_s[Z_AXIS];
      current_position[Z_AXIS] = z;
      line_to_current_position();
    }

  #endif

  stepper.synchronize();

  feedrate_mm_s = old_feedrate_mm_s;

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("<<< do_blocking_move_to");
  #endif
}
void do_blocking_move_to_x(const float &x, const float &fr_mm_s/*=0.0*/) {
  do_blocking_move_to(x, current_position[Y_AXIS], current_position[Z_AXIS], fr_mm_s);
}
void do_blocking_move_to_z(const float &z, const float &fr_mm_s/*=0.0*/) {
  do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], z, fr_mm_s);
}
void do_blocking_move_to_xy(const float &x, const float &y, const float &fr_mm_s/*=0.0*/) {
  do_blocking_move_to(x, y, current_position[Z_AXIS], fr_mm_s);
}

//
// Prepare to do endstop or probe moves
// with custom feedrates.
//
//  - Save current feedrates
//  - Reset the rate multiplier
//  - Reset the command timeout
//  - Enable the endstops (for endstop moves)
//
static void setup_for_endstop_or_probe_move() {
  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) DEBUG_POS("setup_for_endstop_or_probe_move", current_position);
  #endif
  saved_feedrate_mm_s = feedrate_mm_s;
  saved_feedrate_percentage = feedrate_percentage;
  feedrate_percentage = 100;
  refresh_cmd_timeout();
}

static void clean_up_after_endstop_or_probe_move() {
  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) DEBUG_POS("clean_up_after_endstop_or_probe_move", current_position);
  #endif
  feedrate_mm_s = saved_feedrate_mm_s;
  feedrate_percentage = saved_feedrate_percentage;
  refresh_cmd_timeout();
}

#if HAS_BED_PROBE
  /**
   * Raise Z to a minimum height to make room for a probe to move
   */
  inline void do_probe_raise(float z_raise) {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOPAIR("do_probe_raise(", z_raise);
        SERIAL_ECHOLNPGM(")");
      }
    #endif

    float z_dest = LOGICAL_Z_POSITION(z_raise);
    if (zprobe_zoffset < 0) z_dest -= zprobe_zoffset;

    if (z_dest > current_position[Z_AXIS])
      do_blocking_move_to_z(z_dest);
  }

#endif //HAS_BED_PROBE

#if ENABLED(Z_PROBE_ALLEN_KEY) || ENABLED(Z_PROBE_SLED) || HAS_PROBING_PROCEDURE || HOTENDS > 1 || ENABLED(NOZZLE_CLEAN_FEATURE) || ENABLED(NOZZLE_PARK_FEATURE)
  static bool axis_unhomed_error(const bool x, const bool y, const bool z) {
    const bool xx = x && !axis_homed[X_AXIS],
               yy = y && !axis_homed[Y_AXIS],
               zz = z && !axis_homed[Z_AXIS];
    if (xx || yy || zz) {
      SERIAL_ECHO_START;
      SERIAL_ECHOPGM(MSG_HOME " ");
      if (xx) SERIAL_ECHOPGM(MSG_X);
      if (yy) SERIAL_ECHOPGM(MSG_Y);
      if (zz) SERIAL_ECHOPGM(MSG_Z);
      SERIAL_ECHOLNPGM(" " MSG_FIRST);

      #if ENABLED(ULTRA_LCD)
        char message[3 * (LCD_WIDTH) + 1] = ""; // worst case is kana.utf with up to 3*LCD_WIDTH+1
        strcat_P(message, PSTR(MSG_HOME " "));
        if (xx) strcat_P(message, PSTR(MSG_X));
        if (yy) strcat_P(message, PSTR(MSG_Y));
        if (zz) strcat_P(message, PSTR(MSG_Z));
        strcat_P(message, PSTR(" " MSG_FIRST));
        lcd_setstatus(message);
      #endif
      return true;
    }
    return false;
  }
#endif

#if ENABLED(Z_PROBE_SLED)

  #ifndef SLED_DOCKING_OFFSET
    #define SLED_DOCKING_OFFSET 0
  #endif

  /**
   * Method to dock/undock a sled designed by Charles Bell.
   *
   * stow[in]     If false, move to MAX_X and engage the solenoid
   *              If true, move to MAX_X and release the solenoid
   */
  static void dock_sled(bool stow) {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOPAIR("dock_sled(", stow);
        SERIAL_ECHOLNPGM(")");
      }
    #endif

    // Dock sled a bit closer to ensure proper capturing
    do_blocking_move_to_x(X_MAX_POS + SLED_DOCKING_OFFSET - ((stow) ? 1 : 0));

    #if PIN_EXISTS(SLED)
      digitalWrite(SLED_PIN, !stow); // switch solenoid
    #endif
  }

#endif // Z_PROBE_SLED
#if ENABLED(Z_PROBE_ALLEN_KEY)
  void run_deploy_moves_script() {
    #if defined(Z_PROBE_ALLEN_KEY_DEPLOY_1_X) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_1_Y) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_1_Z)
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_1_X
        #define Z_PROBE_ALLEN_KEY_DEPLOY_1_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_1_Y
        #define Z_PROBE_ALLEN_KEY_DEPLOY_1_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_1_Z
        #define Z_PROBE_ALLEN_KEY_DEPLOY_1_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_1_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_DEPLOY_1_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_DEPLOY_1_X, Z_PROBE_ALLEN_KEY_DEPLOY_1_Y, Z_PROBE_ALLEN_KEY_DEPLOY_1_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_DEPLOY_1_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_DEPLOY_2_X) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_2_Y) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_2_Z)
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_2_X
        #define Z_PROBE_ALLEN_KEY_DEPLOY_2_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_2_Y
        #define Z_PROBE_ALLEN_KEY_DEPLOY_2_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_2_Z
        #define Z_PROBE_ALLEN_KEY_DEPLOY_2_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_2_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_DEPLOY_2_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_DEPLOY_2_X, Z_PROBE_ALLEN_KEY_DEPLOY_2_Y, Z_PROBE_ALLEN_KEY_DEPLOY_2_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_DEPLOY_2_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_DEPLOY_3_X) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_3_Y) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_3_Z)
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_3_X
        #define Z_PROBE_ALLEN_KEY_DEPLOY_3_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_3_Y
        #define Z_PROBE_ALLEN_KEY_DEPLOY_3_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_3_Z
        #define Z_PROBE_ALLEN_KEY_DEPLOY_3_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_3_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_DEPLOY_3_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_DEPLOY_3_X, Z_PROBE_ALLEN_KEY_DEPLOY_3_Y, Z_PROBE_ALLEN_KEY_DEPLOY_3_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_DEPLOY_3_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_DEPLOY_4_X) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_4_Y) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_4_Z)
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_4_X
        #define Z_PROBE_ALLEN_KEY_DEPLOY_4_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_4_Y
        #define Z_PROBE_ALLEN_KEY_DEPLOY_4_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_4_Z
        #define Z_PROBE_ALLEN_KEY_DEPLOY_4_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_4_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_DEPLOY_4_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_DEPLOY_4_X, Z_PROBE_ALLEN_KEY_DEPLOY_4_Y, Z_PROBE_ALLEN_KEY_DEPLOY_4_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_DEPLOY_4_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_DEPLOY_5_X) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_5_Y) || defined(Z_PROBE_ALLEN_KEY_DEPLOY_5_Z)
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_5_X
        #define Z_PROBE_ALLEN_KEY_DEPLOY_5_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_5_Y
        #define Z_PROBE_ALLEN_KEY_DEPLOY_5_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_5_Z
        #define Z_PROBE_ALLEN_KEY_DEPLOY_5_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_DEPLOY_5_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_DEPLOY_5_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_DEPLOY_5_X, Z_PROBE_ALLEN_KEY_DEPLOY_5_Y, Z_PROBE_ALLEN_KEY_DEPLOY_5_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_DEPLOY_5_FEEDRATE));
    #endif
  }
  void run_stow_moves_script() {
    #if defined(Z_PROBE_ALLEN_KEY_STOW_1_X) || defined(Z_PROBE_ALLEN_KEY_STOW_1_Y) || defined(Z_PROBE_ALLEN_KEY_STOW_1_Z)
      #ifndef Z_PROBE_ALLEN_KEY_STOW_1_X
        #define Z_PROBE_ALLEN_KEY_STOW_1_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_1_Y
        #define Z_PROBE_ALLEN_KEY_STOW_1_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_1_Z
        #define Z_PROBE_ALLEN_KEY_STOW_1_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_1_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_STOW_1_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_STOW_1_X, Z_PROBE_ALLEN_KEY_STOW_1_Y, Z_PROBE_ALLEN_KEY_STOW_1_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_STOW_1_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_STOW_2_X) || defined(Z_PROBE_ALLEN_KEY_STOW_2_Y) || defined(Z_PROBE_ALLEN_KEY_STOW_2_Z)
      #ifndef Z_PROBE_ALLEN_KEY_STOW_2_X
        #define Z_PROBE_ALLEN_KEY_STOW_2_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_2_Y
        #define Z_PROBE_ALLEN_KEY_STOW_2_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_2_Z
        #define Z_PROBE_ALLEN_KEY_STOW_2_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_2_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_STOW_2_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_STOW_2_X, Z_PROBE_ALLEN_KEY_STOW_2_Y, Z_PROBE_ALLEN_KEY_STOW_2_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_STOW_2_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_STOW_3_X) || defined(Z_PROBE_ALLEN_KEY_STOW_3_Y) || defined(Z_PROBE_ALLEN_KEY_STOW_3_Z)
      #ifndef Z_PROBE_ALLEN_KEY_STOW_3_X
        #define Z_PROBE_ALLEN_KEY_STOW_3_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_3_Y
        #define Z_PROBE_ALLEN_KEY_STOW_3_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_3_Z
        #define Z_PROBE_ALLEN_KEY_STOW_3_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_3_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_STOW_3_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_STOW_3_X, Z_PROBE_ALLEN_KEY_STOW_3_Y, Z_PROBE_ALLEN_KEY_STOW_3_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_STOW_3_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_STOW_4_X) || defined(Z_PROBE_ALLEN_KEY_STOW_4_Y) || defined(Z_PROBE_ALLEN_KEY_STOW_4_Z)
      #ifndef Z_PROBE_ALLEN_KEY_STOW_4_X
        #define Z_PROBE_ALLEN_KEY_STOW_4_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_4_Y
        #define Z_PROBE_ALLEN_KEY_STOW_4_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_4_Z
        #define Z_PROBE_ALLEN_KEY_STOW_4_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_4_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_STOW_4_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_STOW_4_X, Z_PROBE_ALLEN_KEY_STOW_4_Y, Z_PROBE_ALLEN_KEY_STOW_4_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_STOW_4_FEEDRATE));
    #endif
    #if defined(Z_PROBE_ALLEN_KEY_STOW_5_X) || defined(Z_PROBE_ALLEN_KEY_STOW_5_Y) || defined(Z_PROBE_ALLEN_KEY_STOW_5_Z)
      #ifndef Z_PROBE_ALLEN_KEY_STOW_5_X
        #define Z_PROBE_ALLEN_KEY_STOW_5_X current_position[X_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_5_Y
        #define Z_PROBE_ALLEN_KEY_STOW_5_Y current_position[Y_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_5_Z
        #define Z_PROBE_ALLEN_KEY_STOW_5_Z current_position[Z_AXIS]
      #endif
      #ifndef Z_PROBE_ALLEN_KEY_STOW_5_FEEDRATE
        #define Z_PROBE_ALLEN_KEY_STOW_5_FEEDRATE 0.0
      #endif
      do_blocking_move_to(Z_PROBE_ALLEN_KEY_STOW_5_X, Z_PROBE_ALLEN_KEY_STOW_5_Y, Z_PROBE_ALLEN_KEY_STOW_5_Z, MMM_TO_MMS(Z_PROBE_ALLEN_KEY_STOW_5_FEEDRATE));
    #endif
  }
#endif

#if HAS_BED_PROBE

 // TRIGGERED_WHEN_STOWED_TEST can easily be extended to servo probes, ... if needed.
  #if ENABLED(PROBE_IS_TRIGGERED_WHEN_STOWED_TEST)
    #if ENABLED(Z_MIN_PROBE_ENDSTOP)
      #define _TRIGGERED_WHEN_STOWED_TEST (READ(Z_MIN_PROBE_PIN) != Z_MIN_PROBE_ENDSTOP_INVERTING)
    #else
      #define _TRIGGERED_WHEN_STOWED_TEST (READ(Z_MIN_PIN) != Z_MIN_ENDSTOP_INVERTING)
    #endif
  #endif

  #define DEPLOY_PROBE() set_probe_deployed(true)
  #define STOW_PROBE() set_probe_deployed(false)

  #if ENABLED(BLTOUCH)
    FORCE_INLINE void set_bltouch_deployed(const bool &deploy) {
      servo[Z_ENDSTOP_SERVO_NR].move(deploy ? BLTOUCH_DEPLOY : BLTOUCH_STOW);
    }
  #endif

  // returns false for ok and true for failure
  static bool set_probe_deployed(bool deploy) {

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        DEBUG_POS("set_probe_deployed", current_position);
        SERIAL_ECHOLNPAIR("deploy: ", deploy);
      }
    #endif

    if (endstops.z_probe_enabled == deploy) return false;

    // Make room for probe
    do_probe_raise(_Z_CLEARANCE_DEPLOY_PROBE);

    // When deploying make sure BLTOUCH is not already triggered
    #if ENABLED(BLTOUCH)
      if (deploy && TEST_BLTOUCH()) { stop(); return true; }
    #endif

    #if ENABLED(Z_PROBE_SLED)
      if (axis_unhomed_error(true, false, false)) { stop(); return true; }
    #elif ENABLED(Z_PROBE_ALLEN_KEY)
      if (axis_unhomed_error(true, true,  true )) { stop(); return true; }
    #endif

    float oldXpos = current_position[X_AXIS],
          oldYpos = current_position[Y_AXIS];

    #ifdef _TRIGGERED_WHEN_STOWED_TEST

      // If endstop is already false, the Z probe is deployed
      if (_TRIGGERED_WHEN_STOWED_TEST == deploy) {     // closed after the probe specific actions.
                                                       // Would a goto be less ugly?
        //while (!_TRIGGERED_WHEN_STOWED_TEST) idle(); // would offer the opportunity
                                                       // for a triggered when stowed manual probe.

        if (!deploy) endstops.enable_z_probe(false); // Switch off triggered when stowed probes early
                                                     // otherwise an Allen-Key probe can't be stowed.
    #endif

        #if ENABLED(Z_PROBE_SLED)

          dock_sled(!deploy);

        #elif HAS_Z_SERVO_ENDSTOP && DISABLED(BLTOUCH)

          servo[Z_ENDSTOP_SERVO_NR].move(z_servo_angle[deploy ? 0 : 1]);

        #elif ENABLED(Z_PROBE_ALLEN_KEY)

          deploy ? run_deploy_moves_script() : run_stow_moves_script();

        #endif

    #ifdef _TRIGGERED_WHEN_STOWED_TEST
      } // _TRIGGERED_WHEN_STOWED_TEST == deploy

      if (_TRIGGERED_WHEN_STOWED_TEST == deploy) { // State hasn't changed?

        if (IsRunning()) {
          SERIAL_ERROR_START;
          SERIAL_ERRORLNPGM("Z-Probe failed");
          LCD_ALERTMESSAGEPGM("Err: ZPROBE");
        }
        stop();
        return true;

      } // _TRIGGERED_WHEN_STOWED_TEST == deploy

    #endif

    do_blocking_move_to(oldXpos, oldYpos, current_position[Z_AXIS]); // return to position before deploy
    endstops.enable_z_probe(deploy);
    return false;
  }

  static void do_probe_move(float z, float fr_mm_m) {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS(">>> do_probe_move", current_position);
    #endif

    // Deploy BLTouch at the start of any probe
    #if ENABLED(BLTOUCH)
      set_bltouch_deployed(true);
    #endif

    // Move down until probe triggered
    do_blocking_move_to_z(LOGICAL_Z_POSITION(z), MMM_TO_MMS(fr_mm_m));

    // Retract BLTouch immediately after a probe
    #if ENABLED(BLTOUCH)
      set_bltouch_deployed(false);
    #endif

    // Clear endstop flags
    endstops.hit_on_purpose();

    // Tell the planner where we actually are
    planner.sync_from_steppers();

    // Get Z where the steppers were interrupted
    set_current_from_steppers_for_axis(Z_AXIS);

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("<<< do_probe_move", current_position);
    #endif
  }

  // Do a single Z probe and return with current_position[Z_AXIS]
  // at the height where the probe triggered.
  static float run_z_probe() {

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS(">>> run_z_probe", current_position);
    #endif

    // Prevent stepper_inactive_time from running out and EXTRUDER_RUNOUT_PREVENT from extruding
    refresh_cmd_timeout();

    #if ENABLED(PROBE_DOUBLE_TOUCH)

      // Do a first probe at the fast speed
      do_probe_move(-(Z_MAX_LENGTH) - 10, Z_PROBE_SPEED_FAST);

      // move up by the bump distance
      do_blocking_move_to_z(current_position[Z_AXIS] + home_bump_mm(Z_AXIS), MMM_TO_MMS(Z_PROBE_SPEED_FAST));

    #else

      // If the nozzle is above the travel height then
      // move down quickly before doing the slow probe
      float z = LOGICAL_Z_POSITION(Z_CLEARANCE_BETWEEN_PROBES);
      if (z < current_position[Z_AXIS])
        do_blocking_move_to_z(z, MMM_TO_MMS(Z_PROBE_SPEED_FAST));

    #endif

    // move down slowly to find bed
    do_probe_move(-(Z_MAX_LENGTH) - 10, Z_PROBE_SPEED_SLOW);

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("<<< run_z_probe", current_position);
    #endif

    return current_position[Z_AXIS];
  }

  //
  // - Move to the given XY
  // - Deploy the probe, if not already deployed
  // - Probe the bed, get the Z position
  // - Depending on the 'stow' flag
  //   - Stow the probe, or
  //   - Raise to the BETWEEN height
  // - Return the probed Z position
  //
  static float probe_pt(const float &x, const float &y, bool stow = true, int verbose_level = 1) {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOPAIR(">>> probe_pt(", x);
        SERIAL_ECHOPAIR(", ", y);
        SERIAL_ECHOPAIR(", ", stow ? "stow" : "no stow");
        SERIAL_ECHOLNPGM(")");
        DEBUG_POS("", current_position);
      }
    #endif

    float old_feedrate_mm_s = feedrate_mm_s;

    // Ensure a minimum height before moving the probe
    do_probe_raise(Z_CLEARANCE_BETWEEN_PROBES);

    // Move to the XY where we shall probe
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOPAIR("> do_blocking_move_to_xy(", x - (X_PROBE_OFFSET_FROM_EXTRUDER));
        SERIAL_ECHOPAIR(", ", y - (Y_PROBE_OFFSET_FROM_EXTRUDER));
        SERIAL_ECHOLNPGM(")");
      }
    #endif

    feedrate_mm_s = XY_PROBE_FEEDRATE_MM_S;

    // Move the probe to the given XY
    do_blocking_move_to_xy(x - (X_PROBE_OFFSET_FROM_EXTRUDER), y - (Y_PROBE_OFFSET_FROM_EXTRUDER));

    if (DEPLOY_PROBE()) return NAN;

    float measured_z = run_z_probe();

    if (!stow)
      do_probe_raise(Z_CLEARANCE_BETWEEN_PROBES);
    else
      if (STOW_PROBE()) return NAN;

    if (verbose_level > 2) {
      SERIAL_PROTOCOLPGM("Bed X: ");
      SERIAL_PROTOCOL_F(x, 3);
      SERIAL_PROTOCOLPGM(" Y: ");
      SERIAL_PROTOCOL_F(y, 3);
      SERIAL_PROTOCOLPGM(" Z: ");
      SERIAL_PROTOCOL_F(measured_z, 3);
      SERIAL_EOL;
    }

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("<<< probe_pt");
    #endif

    feedrate_mm_s = old_feedrate_mm_s;

    return measured_z;
  }

#endif // HAS_BED_PROBE

#if ENABLED(AUTO_BED_LEVELING_FEATURE)

  /**
   * Reset calibration results to zero.
   *
   * TODO: Proper functions to disable / enable
   *       bed leveling via a flag, correcting the
   *       current position in each case.
   */
  void reset_bed_level() {
    planner.abl_enabled = false;
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("reset_bed_level");
    #endif
    #if ENABLED(AUTO_BED_LEVELING_LINEAR)
      planner.bed_level_matrix.set_to_identity();
    #elif ENABLED(AUTO_BED_LEVELING_NONLINEAR)
      memset(bed_level_grid, 0, sizeof(bed_level_grid));
    #endif
  }

#endif // AUTO_BED_LEVELING_FEATURE

#if ENABLED(AUTO_BED_LEVELING_NONLINEAR)

  /**
   * Extrapolate a single point from its neighbors
   */
  static void extrapolate_one_point(uint8_t x, uint8_t y, int8_t xdir, int8_t ydir) {
    if (bed_level_grid[x][y]) return;  // Don't overwrite good values.
    float a = 2 * bed_level_grid[x + xdir][y] - bed_level_grid[x + xdir * 2][y], // Left to right.
          b = 2 * bed_level_grid[x][y + ydir] - bed_level_grid[x][y + ydir * 2], // Front to back.
          c = 2 * bed_level_grid[x + xdir][y + ydir] - bed_level_grid[x + xdir * 2][y + ydir * 2]; // Diagonal.
    // Median is robust (ignores outliers).
    bed_level_grid[x][y] = (a < b) ? ((b < c) ? b : (c < a) ? a : c)
                                   : ((c < b) ? b : (a < c) ? a : c);
  }

  /**
   * Fill in the unprobed points (corners of circular print surface)
   * using linear extrapolation, away from the center.
   */
  static void extrapolate_unprobed_bed_level() {
    int half_x = (ABL_GRID_POINTS_X - 1) / 2,
        half_y = (ABL_GRID_POINTS_Y - 1) / 2;
    for (uint8_t y = 0; y <= half_y; y++) {
      for (uint8_t x = 0; x <= half_x; x++) {
        if (x + y < 3) continue;
        extrapolate_one_point(half_x - x, half_y - y, x > 1 ? +1 : 0, y > 1 ? +1 : 0);
        extrapolate_one_point(half_x + x, half_y - y, x > 1 ? -1 : 0, y > 1 ? +1 : 0);
        extrapolate_one_point(half_x - x, half_y + y, x > 1 ? +1 : 0, y > 1 ? -1 : 0);
        extrapolate_one_point(half_x + x, half_y + y, x > 1 ? -1 : 0, y > 1 ? -1 : 0);
      }
    }
  }

  /**
   * Print calibration results for plotting or manual frame adjustment.
   */
  static void print_bed_level() {
    for (uint8_t y = 0; y < ABL_GRID_POINTS_Y; y++) {
      for (uint8_t x = 0; x < ABL_GRID_POINTS_X; x++) {
        SERIAL_PROTOCOL_F(bed_level_grid[x][y], 2);
        SERIAL_PROTOCOLCHAR(' ');
      }
      SERIAL_EOL;
    }
  }

#endif // AUTO_BED_LEVELING_NONLINEAR

/**
 * Home an individual linear axis
 */
static void do_homing_move(const AxisEnum axis, float distance, float fr_mm_s=0.0) {

  #if HOMING_Z_WITH_PROBE && ENABLED(BLTOUCH)
    bool deploy_bltouch = (axis == Z_AXIS && distance < 0);
    if (deploy_bltouch) set_bltouch_deployed(true);
  #endif

  // Tell the planner we're at Z=0
  current_position[axis] = 0;

  #if IS_SCARA
    SYNC_PLAN_POSITION_KINEMATIC();
    current_position[axis] = distance;
    inverse_kinematics(current_position);
    planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], current_position[E_AXIS], fr_mm_s ? fr_mm_s : homing_feedrate_mm_s[axis], active_extruder);
  #else
    sync_plan_position();
    current_position[axis] = distance;
    planner.buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], fr_mm_s ? fr_mm_s : homing_feedrate_mm_s[axis], active_extruder);
  #endif

  stepper.synchronize();

  #if HOMING_Z_WITH_PROBE && ENABLED(BLTOUCH)
    if (deploy_bltouch) set_bltouch_deployed(false);
  #endif

  endstops.hit_on_purpose();
}

/**
 * Home an individual "raw axis" to its endstop.
 * This applies to XYZ on Cartesian and Core robots, and
 * to the individual ABC steppers on DELTA and SCARA.
 *
 * At the end of the procedure the axis is marked as
 * homed and the current position of that axis is updated.
 * Kinematic robots should wait till all axes are homed
 * before updating the current position.
 */

#define HOMEAXIS(LETTER) homeaxis(LETTER##_AXIS)

static void homeaxis(AxisEnum axis) {

  #if IS_SCARA
    // Only Z homing (with probe) is permitted
    if (axis != Z_AXIS) { BUZZ(100, 880); return; }
  #else
    #define CAN_HOME(A) \
      (axis == A##_AXIS && ((A##_MIN_PIN > -1 && A##_HOME_DIR < 0) || (A##_MAX_PIN > -1 && A##_HOME_DIR > 0)))
    if (!CAN_HOME(X) && !CAN_HOME(Y) && !CAN_HOME(Z)) return;
  #endif

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOPAIR(">>> homeaxis(", axis_codes[axis]);
      SERIAL_ECHOLNPGM(")");
    }
  #endif

  int axis_home_dir =
    #if ENABLED(DUAL_X_CARRIAGE)
      (axis == X_AXIS) ? x_home_dir(active_extruder) :
    #endif
    home_dir(axis);

  // Homing Z towards the bed? Deploy the Z probe or endstop.
  #if HOMING_Z_WITH_PROBE
    if (axis == Z_AXIS && DEPLOY_PROBE()) return;
  #endif

  // Set a flag for Z motor locking
  #if ENABLED(Z_DUAL_ENDSTOPS)
    if (axis == Z_AXIS) stepper.set_homing_flag(true);
  #endif

  // Fast move towards endstop until triggered
  do_homing_move(axis, 1.5 * max_length(axis) * axis_home_dir);

  // When homing Z with probe respect probe clearance
  const float bump = axis_home_dir * (
    #if HOMING_Z_WITH_PROBE
      (axis == Z_AXIS) ? max(Z_CLEARANCE_BETWEEN_PROBES, home_bump_mm(Z_AXIS)) :
    #endif
    home_bump_mm(axis)
  );

  // If a second homing move is configured...
  if (bump) {
    // Move away from the endstop by the axis HOME_BUMP_MM
    do_homing_move(axis, -bump);
    // Slow move towards endstop until triggered
    do_homing_move(axis, 2 * bump, get_homing_bump_feedrate(axis));
  }

  #if ENABLED(Z_DUAL_ENDSTOPS)
    if (axis == Z_AXIS) {
      float adj = fabs(z_endstop_adj);
      bool lockZ1;
      if (axis_home_dir > 0) {
        adj = -adj;
        lockZ1 = (z_endstop_adj > 0);
      }
      else
        lockZ1 = (z_endstop_adj < 0);

      if (lockZ1) stepper.set_z_lock(true); else stepper.set_z2_lock(true);

      // Move to the adjusted endstop height
      do_homing_move(axis, adj);

      if (lockZ1) stepper.set_z_lock(false); else stepper.set_z2_lock(false);
      stepper.set_homing_flag(false);
    } // Z_AXIS
  #endif

  #if IS_SCARA

    set_axis_is_at_home(axis);
    SYNC_PLAN_POSITION_KINEMATIC();

  #elif ENABLED(DELTA)

    // Delta has already moved all three towers up in G28
    // so here it re-homes each tower in turn.
    // Delta homing treats the axes as normal linear axes.

    // retrace by the amount specified in endstop_adj
    if (endstop_adj[axis] * Z_HOME_DIR < 0) {
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) {
          SERIAL_ECHOPAIR("> endstop_adj = ", endstop_adj[axis] * Z_HOME_DIR);
          DEBUG_POS("", current_position);
        }
      #endif
      do_homing_move(axis, endstop_adj[axis]);
    }

  #else

    // For cartesian/core machines,
    // set the axis to its home position
    set_axis_is_at_home(axis);
    sync_plan_position();

    destination[axis] = current_position[axis];

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("> AFTER set_axis_is_at_home", current_position);
    #endif

  #endif

  // Put away the Z probe
  #if HOMING_Z_WITH_PROBE
    if (axis == Z_AXIS && STOW_PROBE()) return;
  #endif

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOPAIR("<<< homeaxis(", axis_codes[axis]);
      SERIAL_ECHOLNPGM(")");
    }
  #endif
} // homeaxis()

#if ENABLED(FWRETRACT)

  void retract(bool retracting, bool swapping = false) {

    if (retracting == retracted[active_extruder]) return;

    float old_feedrate_mm_s = feedrate_mm_s;

    set_destination_to_current();

    if (retracting) {

      feedrate_mm_s = retract_feedrate_mm_s;
      current_position[E_AXIS] += (swapping ? retract_length_swap : retract_length) / volumetric_multiplier[active_extruder];
      sync_plan_position_e();
      prepare_move_to_destination();

      if (retract_zlift > 0.01) {
        current_position[Z_AXIS] -= retract_zlift;
        SYNC_PLAN_POSITION_KINEMATIC();
        prepare_move_to_destination();
      }
    }
    else {

      if (retract_zlift > 0.01) {
        current_position[Z_AXIS] += retract_zlift;
        SYNC_PLAN_POSITION_KINEMATIC();
      }

      feedrate_mm_s = retract_recover_feedrate_mm_s;
      float move_e = swapping ? retract_length_swap + retract_recover_length_swap : retract_length + retract_recover_length;
      current_position[E_AXIS] -= move_e / volumetric_multiplier[active_extruder];
      sync_plan_position_e();
      prepare_move_to_destination();
    }

    feedrate_mm_s = old_feedrate_mm_s;
    retracted[active_extruder] = retracting;

  } // retract()

#endif // FWRETRACT

#if ENABLED(MIXING_EXTRUDER)

  void normalize_mix() {
    float mix_total = 0.0;
    for (int i = 0; i < MIXING_STEPPERS; i++) {
      float v = mixing_factor[i];
      if (v < 0) v = mixing_factor[i] = 0;
      mix_total += v;
    }
    // Scale all values if they don't add up to ~1.0
    if (mix_total < 0.9999 || mix_total > 1.0001) {
      SERIAL_PROTOCOLLNPGM("Warning: Mix factors must add up to 1.0. Scaling.");
      float mix_scale = 1.0 / mix_total;
      for (int i = 0; i < MIXING_STEPPERS; i++)
        mixing_factor[i] *= mix_scale;
    }
  }

  #if ENABLED(DIRECT_MIXING_IN_G1)
    // Get mixing parameters from the GCode
    // Factors that are left out are set to 0
    // The total "must" be 1.0 (but it will be normalized)
    void gcode_get_mix() {
      const char* mixing_codes = "ABCDHI";
      for (int i = 0; i < MIXING_STEPPERS; i++)
        mixing_factor[i] = code_seen(mixing_codes[i]) ? code_value_float() : 0;

      normalize_mix();
    }
  #endif

#endif

/**
 * ***************************************************************************
 * ***************************** G-CODE HANDLING *****************************
 * ***************************************************************************
 */

/**
 * Set XYZE destination and feedrate from the current GCode command
 *
 *  - Set destination from included axis codes
 *  - Set to current for missing axis codes
 *  - Set the feedrate, if included
 */
void gcode_get_destination() {
  LOOP_XYZE(i) {
    if (code_seen(axis_codes[i]))
      destination[i] = code_value_axis_units(i) + (axis_relative_modes[i] || relative_mode ? current_position[i] : 0);
    else
      destination[i] = current_position[i];
  }

  if (code_seen('F') && code_value_linear_units() > 0.0)
    feedrate_mm_s = MMM_TO_MMS(code_value_linear_units());

  #if ENABLED(PRINTCOUNTER)
    if (!DEBUGGING(DRYRUN))
      print_job_timer.incFilamentUsed(destination[E_AXIS] - current_position[E_AXIS]);
  #endif

  // Get ABCDHI mixing factors
  #if ENABLED(MIXING_EXTRUDER) && ENABLED(DIRECT_MIXING_IN_G1)
    gcode_get_mix();
  #endif
}

void unknown_command_error() {
  SERIAL_ECHO_START;
  SERIAL_ECHOPAIR(MSG_UNKNOWN_COMMAND, current_command);
  SERIAL_ECHOLNPGM("\"");
}

#if ENABLED(HOST_KEEPALIVE_FEATURE)

  /**
   * Output a "busy" message at regular intervals
   * while the machine is not accepting commands.
   */
  void host_keepalive() {
    millis_t ms = millis();
    if (host_keepalive_interval && busy_state != NOT_BUSY) {
      if (PENDING(ms, next_busy_signal_ms)) return;
      switch (busy_state) {
        case IN_HANDLER:
        case IN_PROCESS:
          SERIAL_ECHO_START;
          SERIAL_ECHOLNPGM(MSG_BUSY_PROCESSING);
          break;
        case PAUSED_FOR_USER:
          SERIAL_ECHO_START;
          SERIAL_ECHOLNPGM(MSG_BUSY_PAUSED_FOR_USER);
          break;
        case PAUSED_FOR_INPUT:
          SERIAL_ECHO_START;
          SERIAL_ECHOLNPGM(MSG_BUSY_PAUSED_FOR_INPUT);
          break;
        default:
          break;
      }
    }
    next_busy_signal_ms = ms + host_keepalive_interval * 1000UL;
  }

#endif //HOST_KEEPALIVE_FEATURE

bool position_is_reachable(float target[XYZ]
  #if HAS_BED_PROBE
    , bool by_probe=false
  #endif
) {
  float dx = RAW_X_POSITION(target[X_AXIS]),
        dy = RAW_Y_POSITION(target[Y_AXIS]);

  #if HAS_BED_PROBE
    if (by_probe) {
      dx -= X_PROBE_OFFSET_FROM_EXTRUDER;
      dy -= Y_PROBE_OFFSET_FROM_EXTRUDER;
    }
  #endif

  #if IS_SCARA
    #if MIDDLE_DEAD_ZONE_R > 0
      const float R2 = HYPOT2(dx - SCARA_OFFSET_X, dy - SCARA_OFFSET_Y);
      return R2 >= sq(float(MIDDLE_DEAD_ZONE_R)) && R2 <= sq(L1 + L2);
    #else
      return HYPOT2(dx - SCARA_OFFSET_X, dy - SCARA_OFFSET_Y) <= sq(L1 + L2);
    #endif
  #elif ENABLED(DELTA)
    return HYPOT2(dx, dy) <= sq(DELTA_PRINTABLE_RADIUS);
  #else
    const float dz = RAW_Z_POSITION(target[Z_AXIS]);
    return dx >= X_MIN_POS - 0.0001 && dx <= X_MAX_POS + 0.0001
        && dy >= Y_MIN_POS - 0.0001 && dy <= Y_MAX_POS + 0.0001
        && dz >= Z_MIN_POS - 0.0001 && dz <= Z_MAX_POS + 0.0001;
  #endif
}

/**************************************************
 ***************** GCode Handlers *****************
 **************************************************/

/**
 * G0, G1: Coordinated movement of X Y Z E axes
 */
inline void gcode_G0_G1(
  #if IS_SCARA
    bool fast_move=false
  #endif
) {
  if (IsRunning()) {
    gcode_get_destination(); // For X Y Z E F

    #if ENABLED(FWRETRACT)

      if (autoretract_enabled && !(code_seen('X') || code_seen('Y') || code_seen('Z')) && code_seen('E')) {
        float echange = destination[E_AXIS] - current_position[E_AXIS];
        // Is this move an attempt to retract or recover?
        if ((echange < -MIN_RETRACT && !retracted[active_extruder]) || (echange > MIN_RETRACT && retracted[active_extruder])) {
          current_position[E_AXIS] = destination[E_AXIS]; // hide the slicer-generated retract/recover from calculations
          sync_plan_position_e();  // AND from the planner
          retract(!retracted[active_extruder]);
          return;
        }
      }

    #endif //FWRETRACT

    #if IS_SCARA
      fast_move ? prepare_uninterpolated_move_to_destination() : prepare_move_to_destination();
    #else
      prepare_move_to_destination();
    #endif
  }
}

/**
 * G2: Clockwise Arc
 * G3: Counterclockwise Arc
 *
 * This command has two forms: IJ-form and R-form.
 *
 *  - I specifies an X offset. J specifies a Y offset.
 *    At least one of the IJ parameters is required.
 *    X and Y can be omitted to do a complete circle.
 *    The given XY is not error-checked. The arc ends
 *     based on the angle of the destination.
 *    Mixing I or J with R will throw an error.
 *
 *  - R specifies the radius. X or Y is required.
 *    Omitting both X and Y will throw an error.
 *    X or Y must differ from the current XY.
 *    Mixing R with I or J will throw an error.
 *
 *  Examples:
 *
 *    G2 I10           ; CW circle centered at X+10
 *    G3 X20 Y12 R14   ; CCW circle with r=14 ending at X20 Y12
 */
#if ENABLED(ARC_SUPPORT)
  inline void gcode_G2_G3(bool clockwise) {
    if (IsRunning()) {

      #if ENABLED(SF_ARC_FIX)
        bool relative_mode_backup = relative_mode;
        relative_mode = true;
      #endif

      gcode_get_destination();

      #if ENABLED(SF_ARC_FIX)
        relative_mode = relative_mode_backup;
      #endif

      float arc_offset[2] = { 0.0, 0.0 };
      if (code_seen('R')) {
        const float r = code_value_axis_units(X_AXIS),
                    x1 = current_position[X_AXIS], y1 = current_position[Y_AXIS],
                    x2 = destination[X_AXIS], y2 = destination[Y_AXIS];
        if (r && (x2 != x1 || y2 != y1)) {
          const float e = clockwise ? -1 : 1,                     // clockwise -1, counterclockwise 1
                      dx = x2 - x1, dy = y2 - y1,                 // X and Y differences
                      d = HYPOT(dx, dy),                          // Linear distance between the points
                      h = sqrt(sq(r) - sq(d * 0.5)),              // Distance to the arc pivot-point
                      mx = (x1 + x2) * 0.5, my = (y1 + y2) * 0.5, // Point between the two points
                      sx = -dy / d, sy = dx / d,                  // Slope of the perpendicular bisector
                      cx = mx + e * h * sx, cy = my + e * h * sy; // Pivot-point of the arc
          arc_offset[X_AXIS] = cx - x1;
          arc_offset[Y_AXIS] = cy - y1;
        }
      }
      else {
        if (code_seen('I')) arc_offset[X_AXIS] = code_value_axis_units(X_AXIS);
        if (code_seen('J')) arc_offset[Y_AXIS] = code_value_axis_units(Y_AXIS);
      }

      if (arc_offset[0] || arc_offset[1]) {
        // Send an arc to the planner
        plan_arc(destination, arc_offset, clockwise);
        refresh_cmd_timeout();
      }
      else {
        // Bad arguments
        SERIAL_ERROR_START;
        SERIAL_ERRORLNPGM(MSG_ERR_ARC_ARGS);
      }
    }
  }
#endif

/**
 * G4: Dwell S<seconds> or P<milliseconds>
 */
inline void gcode_G4() {
  millis_t dwell_ms = 0;

  if (code_seen('P')) dwell_ms = code_value_millis(); // milliseconds to wait
  if (code_seen('S')) dwell_ms = code_value_millis_from_seconds(); // seconds to wait

  stepper.synchronize();
  refresh_cmd_timeout();
  dwell_ms += previous_cmd_ms;  // keep track of when we started waiting

  if (!lcd_hasstatus()) LCD_MESSAGEPGM(MSG_DWELL);

  while (PENDING(millis(), dwell_ms)) idle();
}

#if ENABLED(BEZIER_CURVE_SUPPORT)

  /**
   * Parameters interpreted according to:
   * http://linuxcnc.org/docs/2.6/html/gcode/gcode.html#sec:G5-Cubic-Spline
   * However I, J omission is not supported at this point; all
   * parameters can be omitted and default to zero.
   */

  /**
   * G5: Cubic B-spline
   */
  inline void gcode_G5() {
    if (IsRunning()) {

      gcode_get_destination();

      float offset[] = {
        code_seen('I') ? code_value_axis_units(X_AXIS) : 0.0,
        code_seen('J') ? code_value_axis_units(Y_AXIS) : 0.0,
        code_seen('P') ? code_value_axis_units(X_AXIS) : 0.0,
        code_seen('Q') ? code_value_axis_units(Y_AXIS) : 0.0
      };

      plan_cubic_move(offset);
    }
  }

#endif // BEZIER_CURVE_SUPPORT

#if ENABLED(FWRETRACT)

  /**
   * G10 - Retract filament according to settings of M207
   * G11 - Recover filament according to settings of M208
   */
  inline void gcode_G10_G11(bool doRetract=false) {
    #if EXTRUDERS > 1
      if (doRetract) {
        retracted_swap[active_extruder] = (code_seen('S') && code_value_bool()); // checks for swap retract argument
      }
    #endif
    retract(doRetract
     #if EXTRUDERS > 1
      , retracted_swap[active_extruder]
     #endif
    );
  }

#endif //FWRETRACT

#if ENABLED(NOZZLE_CLEAN_FEATURE)
  /**
   * G12: Clean the nozzle
   */
  inline void gcode_G12() {
    // Don't allow nozzle cleaning without homing first
    if (axis_unhomed_error(true, true, true)) { return; }

    uint8_t const pattern = code_seen('P') ? code_value_ushort() : 0;
    uint8_t const strokes = code_seen('S') ? code_value_ushort() : NOZZLE_CLEAN_STROKES;
    uint8_t const objects = code_seen('T') ? code_value_ushort() : 3;

    Nozzle::clean(pattern, strokes, objects);
  }
#endif

#if ENABLED(INCH_MODE_SUPPORT)
  /**
   * G20: Set input mode to inches
   */
  inline void gcode_G20() { set_input_linear_units(LINEARUNIT_INCH); }

  /**
   * G21: Set input mode to millimeters
   */
  inline void gcode_G21() { set_input_linear_units(LINEARUNIT_MM); }
#endif

#if ENABLED(NOZZLE_PARK_FEATURE)
  /**
   * G27: Park the nozzle
   */
  inline void gcode_G27() {
    // Don't allow nozzle parking without homing first
    if (axis_unhomed_error(true, true, true)) { return; }
    uint8_t const z_action = code_seen('P') ? code_value_ushort() : 0;
    Nozzle::park(z_action);
  }
#endif // NOZZLE_PARK_FEATURE

#if ENABLED(QUICK_HOME)

  static void quick_home_xy() {

    // Pretend the current position is 0,0
    current_position[X_AXIS] = current_position[Y_AXIS] = 0.0;
    sync_plan_position();

    int x_axis_home_dir =
      #if ENABLED(DUAL_X_CARRIAGE)
        x_home_dir(active_extruder)
      #else
        home_dir(X_AXIS)
      #endif
    ;

    float mlx = max_length(X_AXIS),
          mly = max_length(Y_AXIS),
          mlratio = mlx > mly ? mly / mlx : mlx / mly,
          fr_mm_s = min(homing_feedrate_mm_s[X_AXIS], homing_feedrate_mm_s[Y_AXIS]) * sqrt(sq(mlratio) + 1.0);

    do_blocking_move_to_xy(1.5 * mlx * x_axis_home_dir, 1.5 * mly * home_dir(Y_AXIS), fr_mm_s);
    endstops.hit_on_purpose(); // clear endstop hit flags
    current_position[X_AXIS] = current_position[Y_AXIS] = 0.0;

  }

#endif // QUICK_HOME

#if ENABLED(DEBUG_LEVELING_FEATURE)

  void log_machine_info() {
    SERIAL_ECHOPGM("Machine Type: ");
    #if ENABLED(DELTA)
      SERIAL_ECHOLNPGM("Delta");
    #elif IS_SCARA
      SERIAL_ECHOLNPGM("SCARA");
    #elif ENABLED(COREXY) || ENABLED(COREXZ) || ENABLED(COREYZ)
      SERIAL_ECHOLNPGM("Core");
    #else
      SERIAL_ECHOLNPGM("Cartesian");
    #endif

    SERIAL_ECHOPGM("Probe: ");
    #if ENABLED(FIX_MOUNTED_PROBE)
      SERIAL_ECHOLNPGM("FIX_MOUNTED_PROBE");
    #elif HAS_Z_SERVO_ENDSTOP
      SERIAL_ECHOLNPGM("SERVO PROBE");
    #elif ENABLED(BLTOUCH)
      SERIAL_ECHOLNPGM("BLTOUCH");
    #elif ENABLED(Z_PROBE_SLED)
      SERIAL_ECHOLNPGM("Z_PROBE_SLED");
    #elif ENABLED(Z_PROBE_ALLEN_KEY)
      SERIAL_ECHOLNPGM("Z_PROBE_ALLEN_KEY");
    #else
      SERIAL_ECHOLNPGM("NONE");
    #endif

    #if HAS_BED_PROBE
      SERIAL_ECHOPAIR("Probe Offset X:", X_PROBE_OFFSET_FROM_EXTRUDER);
      SERIAL_ECHOPAIR(" Y:", Y_PROBE_OFFSET_FROM_EXTRUDER);
      SERIAL_ECHOPAIR(" Z:", zprobe_zoffset);
      #if (X_PROBE_OFFSET_FROM_EXTRUDER > 0)
        SERIAL_ECHOPGM(" (Right");
      #elif (X_PROBE_OFFSET_FROM_EXTRUDER < 0)
        SERIAL_ECHOPGM(" (Left");
      #elif (Y_PROBE_OFFSET_FROM_EXTRUDER != 0)
        SERIAL_ECHOPGM(" (Middle");
      #else
        SERIAL_ECHOPGM(" (Aligned With");
      #endif
      #if (Y_PROBE_OFFSET_FROM_EXTRUDER > 0)
        SERIAL_ECHOPGM("-Back");
      #elif (Y_PROBE_OFFSET_FROM_EXTRUDER < 0)
        SERIAL_ECHOPGM("-Front");
      #elif (X_PROBE_OFFSET_FROM_EXTRUDER != 0)
        SERIAL_ECHOPGM("-Center");
      #endif
      if (zprobe_zoffset < 0)
        SERIAL_ECHOPGM(" & Below");
      else if (zprobe_zoffset > 0)
        SERIAL_ECHOPGM(" & Above");
      else
        SERIAL_ECHOPGM(" & Same Z as");
      SERIAL_ECHOLNPGM(" Nozzle)");
    #endif
  }

#endif // DEBUG_LEVELING_FEATURE

#if ENABLED(DELTA)

  /**
   * A delta can only safely home all axes at the same time
   * This is like quick_home_xy() but for 3 towers.
   */
  inline void home_delta() {
    // Init the current position of all carriages to 0,0,0
    memset(current_position, 0, sizeof(current_position));
    sync_plan_position();

    // Move all carriages together linearly until an endstop is hit.
    current_position[X_AXIS] = current_position[Y_AXIS] = current_position[Z_AXIS] = (Z_MAX_LENGTH + 10);
    feedrate_mm_s = homing_feedrate_mm_s[X_AXIS];
    line_to_current_position();
    stepper.synchronize();
    endstops.hit_on_purpose(); // clear endstop hit flags

    // Probably not needed. Double-check this line:
    memset(current_position, 0, sizeof(current_position));

    // At least one carriage has reached the top.
    // Now back off and re-home each carriage separately.
    HOMEAXIS(A);
    HOMEAXIS(B);
    HOMEAXIS(C);

    // Set all carriages to their home positions
    // Do this here all at once for Delta, because
    // XYZ isn't ABC. Applying this per-tower would
    // give the impression that they are the same.
    LOOP_XYZ(i) set_axis_is_at_home((AxisEnum)i);

    SYNC_PLAN_POSITION_KINEMATIC();

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("(DELTA)", current_position);
    #endif
  }

#endif // DELTA

#if ENABLED(Z_SAFE_HOMING)

  inline void home_z_safely() {

    // Disallow Z homing if X or Y are unknown
    if (!axis_known_position[X_AXIS] || !axis_known_position[Y_AXIS]) {
      LCD_MESSAGEPGM(MSG_ERR_Z_HOMING);
      SERIAL_ECHO_START;
      SERIAL_ECHOLNPGM(MSG_ERR_Z_HOMING);
      return;
    }

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("Z_SAFE_HOMING >>>");
    #endif

    SYNC_PLAN_POSITION_KINEMATIC();

    /**
     * Move the Z probe (or just the nozzle) to the safe homing point
     */
    destination[X_AXIS] = LOGICAL_X_POSITION(Z_SAFE_HOMING_X_POINT);
    destination[Y_AXIS] = LOGICAL_Y_POSITION(Z_SAFE_HOMING_Y_POINT);
    destination[Z_AXIS] = current_position[Z_AXIS]; // Z is already at the right height

    if (position_is_reachable(
          destination
          #if HOMING_Z_WITH_PROBE
            , true
          #endif
        )
    ) {
      #if HOMING_Z_WITH_PROBE
        destination[X_AXIS] -= X_PROBE_OFFSET_FROM_EXTRUDER;
        destination[Y_AXIS] -= Y_PROBE_OFFSET_FROM_EXTRUDER;
      #endif
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) DEBUG_POS("Z_SAFE_HOMING", destination);
      #endif
      do_blocking_move_to_xy(destination[X_AXIS], destination[Y_AXIS]);
      HOMEAXIS(Z);
    }
    else {
      LCD_MESSAGEPGM(MSG_ZPROBE_OUT);
      SERIAL_ECHO_START;
      SERIAL_ECHOLNPGM(MSG_ZPROBE_OUT);
    }

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("<<< Z_SAFE_HOMING");
    #endif
  }

#endif // Z_SAFE_HOMING

/**
 * G28: Home all axes according to settings
 *
 * Parameters
 *
 *  None  Home to all axes with no parameters.
 *        With QUICK_HOME enabled XY will home together, then Z.
 *
 * Cartesian parameters
 *
 *  X   Home to the X endstop
 *  Y   Home to the Y endstop
 *  Z   Home to the Z endstop
 *
 */
inline void gcode_G28() {

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOLNPGM(">>> gcode_G28");
      log_machine_info();
    }
  #endif

  // Wait for planner moves to finish!
  stepper.synchronize();

  // For auto bed leveling, clear the level matrix
  #if ENABLED(AUTO_BED_LEVELING_FEATURE)
    reset_bed_level();
  #endif

  // Always home with tool 0 active
  #if HOTENDS > 1
    uint8_t old_tool_index = active_extruder;
    tool_change(0, 0, true);
  #endif

  #if ENABLED(DUAL_X_CARRIAGE) || ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
    extruder_duplication_enabled = false;
  #endif

  /**
   * For mesh bed leveling deactivate the mesh calculations, will be turned
   * on again when homing all axis
   */
  #if ENABLED(MESH_BED_LEVELING)
    float pre_home_z = MESH_HOME_SEARCH_Z;
    if (mbl.active()) {
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("MBL was active");
      #endif
      // Save known Z position if already homed
      if (axis_homed[X_AXIS] && axis_homed[Y_AXIS] && axis_homed[Z_AXIS]) {
        pre_home_z = current_position[Z_AXIS];
        pre_home_z += mbl.get_z(RAW_CURRENT_POSITION(X_AXIS), RAW_CURRENT_POSITION(Y_AXIS));
      }
      mbl.set_active(false);
      current_position[Z_AXIS] = pre_home_z;
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) DEBUG_POS("Set Z to pre_home_z", current_position);
      #endif
    }
  #endif

  setup_for_endstop_or_probe_move();
  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("> endstops.enable(true)");
  #endif
  endstops.enable(true); // Enable endstops for next homing move

  #if ENABLED(DELTA)

    home_delta();

  #else // NOT DELTA

    bool homeX = code_seen('X'), homeY = code_seen('Y'), homeZ = code_seen('Z');

    home_all_axis = (!homeX && !homeY && !homeZ) || (homeX && homeY && homeZ);

    set_destination_to_current();

    #if Z_HOME_DIR > 0  // If homing away from BED do Z first

      if (home_all_axis || homeZ) {
        HOMEAXIS(Z);
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("> HOMEAXIS(Z)", current_position);
        #endif
      }

    #else

      if (home_all_axis || homeX || homeY) {
        // Raise Z before homing any other axes and z is not already high enough (never lower z)
        destination[Z_AXIS] = LOGICAL_Z_POSITION(Z_HOMING_HEIGHT);
        if (destination[Z_AXIS] > current_position[Z_AXIS]) {

          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING))
              SERIAL_ECHOLNPAIR("Raise Z (before homing) to ", destination[Z_AXIS]);
          #endif

          do_blocking_move_to_z(destination[Z_AXIS]);
        }
      }

    #endif

    #if ENABLED(QUICK_HOME)

      if (home_all_axis || (homeX && homeY)) quick_home_xy();

    #endif

    #if ENABLED(HOME_Y_BEFORE_X)

      // Home Y
      if (home_all_axis || homeY) {
        HOMEAXIS(Y);
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("> homeY", current_position);
        #endif
      }

    #endif

    // Home X
    if (home_all_axis || homeX) {
      #if ENABLED(DUAL_X_CARRIAGE)
        int tmp_extruder = active_extruder;
        active_extruder = !active_extruder;
        HOMEAXIS(X);
        inactive_extruder_x_pos = RAW_X_POSITION(current_position[X_AXIS]);
        active_extruder = tmp_extruder;
        HOMEAXIS(X);
        // reset state used by the different modes
        memcpy(raised_parked_position, current_position, sizeof(raised_parked_position));
        delayed_move_time = 0;
        active_extruder_parked = true;
      #else
        HOMEAXIS(X);
      #endif
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) DEBUG_POS("> homeX", current_position);
      #endif
    }

    #if DISABLED(HOME_Y_BEFORE_X)
      // Home Y
      if (home_all_axis || homeY) {
        HOMEAXIS(Y);
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("> homeY", current_position);
        #endif
      }
    #endif

    // Home Z last if homing towards the bed
    #if Z_HOME_DIR < 0
      if (home_all_axis || homeZ) {
        #if ENABLED(Z_SAFE_HOMING)
          home_z_safely();
        #else
          HOMEAXIS(Z);
        #endif
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("> (home_all_axis || homeZ) > final", current_position);
        #endif
      } // home_all_axis || homeZ
    #endif // Z_HOME_DIR < 0

    SYNC_PLAN_POSITION_KINEMATIC();

  #endif // !DELTA (gcode_G28)

  endstops.not_homing();

  // Enable mesh leveling again
  #if ENABLED(MESH_BED_LEVELING)
    if (mbl.has_mesh()) {
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("MBL has mesh");
      #endif
      if (home_all_axis || (axis_homed[X_AXIS] && axis_homed[Y_AXIS] && homeZ)) {
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("MBL Z homing");
        #endif
        current_position[Z_AXIS] = MESH_HOME_SEARCH_Z
          #if Z_HOME_DIR > 0
            + Z_MAX_POS
          #endif
        ;
        SYNC_PLAN_POSITION_KINEMATIC();
        mbl.set_active(true);
        #if ENABLED(MESH_G28_REST_ORIGIN)
          current_position[Z_AXIS] = 0.0;
          set_destination_to_current();
          line_to_destination(homing_feedrate_mm_s[Z_AXIS]);
          stepper.synchronize();
          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) DEBUG_POS("MBL Rest Origin", current_position);
          #endif
        #else
          planner.unapply_leveling(current_position);
          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) DEBUG_POS("MBL adjusted MESH_HOME_SEARCH_Z", current_position);
          #endif
        #endif
      }
      else if ((axis_homed[X_AXIS] && axis_homed[Y_AXIS] && axis_homed[Z_AXIS]) && (homeX || homeY)) {
        current_position[Z_AXIS] = pre_home_z;
        SYNC_PLAN_POSITION_KINEMATIC();
        mbl.set_active(true);
        planner.unapply_leveling(current_position);
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("MBL Home X or Y", current_position);
        #endif
      }
    }
  #endif

  #if ENABLED(DELTA)
    // move to a height where we can use the full xy-area
    do_blocking_move_to_z(delta_clip_start_height);
  #endif

  clean_up_after_endstop_or_probe_move();

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("<<< gcode_G28");
  #endif

  // Restore the active tool after homing
  #if HOTENDS > 1
    tool_change(old_tool_index, 0, true);
  #endif

  report_current_position();
}

#if HAS_PROBING_PROCEDURE

  void out_of_range_error(const char* p_edge) {
    SERIAL_PROTOCOLPGM("?Probe ");
    serialprintPGM(p_edge);
    SERIAL_PROTOCOLLNPGM(" position out of range.");
  }

#endif

#if ENABLED(MESH_BED_LEVELING)

  inline void _mbl_goto_xy(float x, float y) {
    float old_feedrate_mm_s = feedrate_mm_s;
    feedrate_mm_s = homing_feedrate_mm_s[X_AXIS];

    current_position[Z_AXIS] = MESH_HOME_SEARCH_Z
      #if Z_CLEARANCE_BETWEEN_PROBES > Z_HOMING_HEIGHT
        + Z_CLEARANCE_BETWEEN_PROBES
      #elif Z_HOMING_HEIGHT > 0
        + Z_HOMING_HEIGHT
      #endif
    ;
    line_to_current_position();

    current_position[X_AXIS] = LOGICAL_X_POSITION(x);
    current_position[Y_AXIS] = LOGICAL_Y_POSITION(y);
    line_to_current_position();

    #if Z_CLEARANCE_BETWEEN_PROBES > 0 || Z_HOMING_HEIGHT > 0
      current_position[Z_AXIS] = LOGICAL_Z_POSITION(MESH_HOME_SEARCH_Z);
      line_to_current_position();
    #endif

    feedrate_mm_s = old_feedrate_mm_s;
    stepper.synchronize();
  }

  /**
   * G29: Mesh-based Z probe, probes a grid and produces a
   *      mesh to compensate for variable bed height
   *
   * Parameters With MESH_BED_LEVELING:
   *
   *  S0              Produce a mesh report
   *  S1              Start probing mesh points
   *  S2              Probe the next mesh point
   *  S3 Xn Yn Zn.nn  Manually modify a single point
   *  S4 Zn.nn        Set z offset. Positive away from bed, negative closer to bed.
   *  S5              Reset and disable mesh
   *
   * The S0 report the points as below
   *
   *  +----> X-axis  1-n
   *  |
   *  |
   *  v Y-axis  1-n
   *
   */
  inline void gcode_G29() {

    static int probe_point = -1;
    MeshLevelingState state = code_seen('S') ? (MeshLevelingState)code_value_byte() : MeshReport;
    if (state < 0 || state > 5) {
      SERIAL_PROTOCOLLNPGM("S out of range (0-5).");
      return;
    }

    int8_t px, py;

    switch (state) {
      case MeshReport:
        if (mbl.has_mesh()) {
          SERIAL_PROTOCOLPAIR("State: ", mbl.active() ? MSG_ON : MSG_OFF);
          SERIAL_PROTOCOLLNPGM("\nNum X,Y: " STRINGIFY(MESH_NUM_X_POINTS) "," STRINGIFY(MESH_NUM_Y_POINTS));
          SERIAL_PROTOCOLLNPGM("Z search height: " STRINGIFY(MESH_HOME_SEARCH_Z));
          SERIAL_PROTOCOLPGM("Z offset: "); SERIAL_PROTOCOL_F(mbl.z_offset, 5);
          SERIAL_PROTOCOLLNPGM("\nMeasured points:");
          for (py = 0; py < MESH_NUM_Y_POINTS; py++) {
            for (px = 0; px < MESH_NUM_X_POINTS; px++) {
              SERIAL_PROTOCOLPGM("  ");
              SERIAL_PROTOCOL_F(mbl.z_values[py][px], 5);
            }
            SERIAL_EOL;
          }
        }
        else
          SERIAL_PROTOCOLLNPGM("Mesh bed leveling not active.");
        break;

      case MeshStart:
        mbl.reset();
        probe_point = 0;
        enqueue_and_echo_commands_P(PSTR("G28\nG29 S2"));
        break;

      case MeshNext:
        if (probe_point < 0) {
          SERIAL_PROTOCOLLNPGM("Start mesh probing with \"G29 S1\" first.");
          return;
        }
        // For each G29 S2...
        if (probe_point == 0) {
          // For the initial G29 S2 make Z a positive value (e.g., 4.0)
          current_position[Z_AXIS] = MESH_HOME_SEARCH_Z
            #if Z_HOME_DIR > 0
              + Z_MAX_POS
            #endif
          ;
          SYNC_PLAN_POSITION_KINEMATIC();
        }
        else {
          // For G29 S2 after adjusting Z.
          mbl.set_zigzag_z(probe_point - 1, current_position[Z_AXIS]);
        }
        // If there's another point to sample, move there with optional lift.
        if (probe_point < (MESH_NUM_X_POINTS) * (MESH_NUM_Y_POINTS)) {
          mbl.zigzag(probe_point, px, py);
          _mbl_goto_xy(mbl.get_probe_x(px), mbl.get_probe_y(py));
          probe_point++;
        }
        else {
          // One last "return to the bed" (as originally coded) at completion
          current_position[Z_AXIS] = MESH_HOME_SEARCH_Z
            #if Z_CLEARANCE_BETWEEN_PROBES > Z_HOMING_HEIGHT
              + Z_CLEARANCE_BETWEEN_PROBES
            #elif Z_HOMING_HEIGHT > 0
              + Z_HOMING_HEIGHT
            #endif
          ;
          line_to_current_position();
          stepper.synchronize();

          // After recording the last point, activate the mbl and home
          SERIAL_PROTOCOLLNPGM("Mesh probing done.");
          probe_point = -1;
          mbl.set_has_mesh(true);
          enqueue_and_echo_commands_P(PSTR("G28"));
        }
        break;

      case MeshSet:
        if (code_seen('X')) {
          px = code_value_int() - 1;
          if (px < 0 || px >= MESH_NUM_X_POINTS) {
            SERIAL_PROTOCOLLNPGM("X out of range (1-" STRINGIFY(MESH_NUM_X_POINTS) ").");
            return;
          }
        }
        else {
          SERIAL_PROTOCOLLNPGM("X not entered.");
          return;
        }
        if (code_seen('Y')) {
          py = code_value_int() - 1;
          if (py < 0 || py >= MESH_NUM_Y_POINTS) {
            SERIAL_PROTOCOLLNPGM("Y out of range (1-" STRINGIFY(MESH_NUM_Y_POINTS) ").");
            return;
          }
        }
        else {
          SERIAL_PROTOCOLLNPGM("Y not entered.");
          return;
        }
        if (code_seen('Z')) {
          mbl.z_values[py][px] = code_value_axis_units(Z_AXIS);
        }
        else {
          SERIAL_PROTOCOLLNPGM("Z not entered.");
          return;
        }
        break;

      case MeshSetZOffset:
        if (code_seen('Z')) {
          mbl.z_offset = code_value_axis_units(Z_AXIS);
        }
        else {
          SERIAL_PROTOCOLLNPGM("Z not entered.");
          return;
        }
        break;

      case MeshReset:
        if (mbl.active()) {
          current_position[Z_AXIS] +=
            mbl.get_z(RAW_CURRENT_POSITION(X_AXIS), RAW_CURRENT_POSITION(Y_AXIS)) - MESH_HOME_SEARCH_Z;
          mbl.reset();
          SYNC_PLAN_POSITION_KINEMATIC();
        }
        else
          mbl.reset();

    } // switch(state)

    report_current_position();
  }

#elif ENABLED(AUTO_BED_LEVELING_FEATURE)

  /**
   * G29: Detailed Z probe, probes the bed at 3 or more points.
   *      Will fail if the printer has not been homed with G28.
   *
   * Enhanced G29 Auto Bed Leveling Probe Routine
   *
   * Parameters With AUTO_BED_LEVELING_GRID:
   *
   *  P  Set the size of the grid that will be probed (P x P points).
   *     Not supported by non-linear delta printer bed leveling.
   *     Example: "G29 P4"
   *
   *  S  Set the XY travel speed between probe points (in units/min)
   *
   *  D  Dry-Run mode. Just evaluate the bed Topology - Don't apply
   *     or clean the rotation Matrix. Useful to check the topology
   *     after a first run of G29.
   *
   *  V  Set the verbose level (0-4). Example: "G29 V3"
   *
   *  T  Generate a Bed Topology Report. Example: "G29 P5 T" for a detailed report.
   *     This is useful for manual bed leveling and finding flaws in the bed (to
   *     assist with part placement).
   *     Not supported by non-linear delta printer bed leveling.
   *
   *  F  Set the Front limit of the probing grid
   *  B  Set the Back limit of the probing grid
   *  L  Set the Left limit of the probing grid
   *  R  Set the Right limit of the probing grid
   *
   * Global Parameters:
   *
   * E/e By default G29 will engage the Z probe, test the bed, then disengage.
   *     Include "E" to engage/disengage the Z probe for each sample.
   *     There's no extra effect if you have a fixed Z probe.
   *     Usage: "G29 E" or "G29 e"
   *
   */
  inline void gcode_G29() {

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOLNPGM(">>> gcode_G29");
        DEBUG_POS("", current_position);
        log_machine_info();
      }
    #endif

    // Don't allow auto-leveling without homing first
    if (axis_unhomed_error(true, true, true)) return;

    int verbose_level = code_seen('V') ? code_value_int() : 1;
    if (verbose_level < 0 || verbose_level > 4) {
      SERIAL_PROTOCOLLNPGM("?(V)erbose Level is implausible (0-4).");
      return;
    }

    bool dryrun = code_seen('D'),
         stow_probe_after_each = code_seen('E');

    #if ENABLED(AUTO_BED_LEVELING_GRID)

      #if ENABLED(AUTO_BED_LEVELING_LINEAR)
        bool do_topography_map = verbose_level > 2 || code_seen('T');
      #endif

      if (verbose_level > 0) {
        SERIAL_PROTOCOLLNPGM("G29 Auto Bed Leveling");
        if (dryrun) SERIAL_PROTOCOLLNPGM("Running in DRY-RUN mode");
      }

      int abl_grid_points_x = ABL_GRID_POINTS_X,
          abl_grid_points_y = ABL_GRID_POINTS_Y;

      #if ENABLED(AUTO_BED_LEVELING_LINEAR)
        if (code_seen('P')) abl_grid_points_x = abl_grid_points_y = code_value_int();
        if (abl_grid_points_x < 2) {
          SERIAL_PROTOCOLLNPGM("?Number of probed (P)oints is implausible (2 minimum).");
          return;
        }
      #endif

      xy_probe_feedrate_mm_s = MMM_TO_MMS(code_seen('S') ? code_value_linear_units() : XY_PROBE_SPEED);

      int left_probe_bed_position = code_seen('L') ? (int)code_value_axis_units(X_AXIS) : LOGICAL_X_POSITION(LEFT_PROBE_BED_POSITION),
          right_probe_bed_position = code_seen('R') ? (int)code_value_axis_units(X_AXIS) : LOGICAL_X_POSITION(RIGHT_PROBE_BED_POSITION),
          front_probe_bed_position = code_seen('F') ? (int)code_value_axis_units(Y_AXIS) : LOGICAL_Y_POSITION(FRONT_PROBE_BED_POSITION),
          back_probe_bed_position = code_seen('B') ? (int)code_value_axis_units(Y_AXIS) : LOGICAL_Y_POSITION(BACK_PROBE_BED_POSITION);

      bool left_out_l = left_probe_bed_position < LOGICAL_X_POSITION(MIN_PROBE_X),
           left_out = left_out_l || left_probe_bed_position > right_probe_bed_position - (MIN_PROBE_EDGE),
           right_out_r = right_probe_bed_position > LOGICAL_X_POSITION(MAX_PROBE_X),
           right_out = right_out_r || right_probe_bed_position < left_probe_bed_position + MIN_PROBE_EDGE,
           front_out_f = front_probe_bed_position < LOGICAL_Y_POSITION(MIN_PROBE_Y),
           front_out = front_out_f || front_probe_bed_position > back_probe_bed_position - (MIN_PROBE_EDGE),
           back_out_b = back_probe_bed_position > LOGICAL_Y_POSITION(MAX_PROBE_Y),
           back_out = back_out_b || back_probe_bed_position < front_probe_bed_position + MIN_PROBE_EDGE;

      if (left_out || right_out || front_out || back_out) {
        if (left_out) {
          out_of_range_error(PSTR("(L)eft"));
          left_probe_bed_position = left_out_l ? LOGICAL_X_POSITION(MIN_PROBE_X) : right_probe_bed_position - (MIN_PROBE_EDGE);
        }
        if (right_out) {
          out_of_range_error(PSTR("(R)ight"));
          right_probe_bed_position = right_out_r ? LOGICAL_Y_POSITION(MAX_PROBE_X) : left_probe_bed_position + MIN_PROBE_EDGE;
        }
        if (front_out) {
          out_of_range_error(PSTR("(F)ront"));
          front_probe_bed_position = front_out_f ? LOGICAL_Y_POSITION(MIN_PROBE_Y) : back_probe_bed_position - (MIN_PROBE_EDGE);
        }
        if (back_out) {
          out_of_range_error(PSTR("(B)ack"));
          back_probe_bed_position = back_out_b ? LOGICAL_Y_POSITION(MAX_PROBE_Y) : front_probe_bed_position + MIN_PROBE_EDGE;
        }
        return;
      }

    #endif // AUTO_BED_LEVELING_GRID

    stepper.synchronize();

    // Disable auto bed leveling during G29
    bool abl_should_reenable = planner.abl_enabled;

    planner.abl_enabled = false;

    if (!dryrun) {
      // Re-orient the current position without leveling
      // based on where the steppers are positioned.
      get_cartesian_from_steppers();
      memcpy(current_position, cartes, sizeof(cartes));

      // Inform the planner about the new coordinates
      SYNC_PLAN_POSITION_KINEMATIC();
    }

    setup_for_endstop_or_probe_move();

    // Deploy the probe. Probe will raise if needed.
    if (DEPLOY_PROBE()) {
      planner.abl_enabled = abl_should_reenable;
      return;
    }

    float xProbe = 0, yProbe = 0, measured_z = 0;

    #if ENABLED(AUTO_BED_LEVELING_GRID)

      // probe at the points of a lattice grid
      const float xGridSpacing = (right_probe_bed_position - left_probe_bed_position) / (abl_grid_points_x - 1),
                  yGridSpacing = (back_probe_bed_position - front_probe_bed_position) / (abl_grid_points_y - 1);

      #if ENABLED(AUTO_BED_LEVELING_NONLINEAR)

        float zoffset = zprobe_zoffset;
        if (code_seen('Z')) zoffset += code_value_axis_units(Z_AXIS);

        if (xGridSpacing != nonlinear_grid_spacing[X_AXIS] || yGridSpacing != nonlinear_grid_spacing[Y_AXIS]) {
          nonlinear_grid_spacing[X_AXIS] = xGridSpacing;
          nonlinear_grid_spacing[Y_AXIS] = yGridSpacing;
          // Can't re-enable (on error) until the new grid is written
          abl_should_reenable = false;
        }

      #elif ENABLED(AUTO_BED_LEVELING_LINEAR_GRID)

        /**
         * solve the plane equation ax + by + d = z
         * A is the matrix with rows [x y 1] for all the probed points
         * B is the vector of the Z positions
         * the normal vector to the plane is formed by the coefficients of the
         * plane equation in the standard form, which is Vx*x+Vy*y+Vz*z+d = 0
         * so Vx = -a Vy = -b Vz = 1 (we want the vector facing towards positive Z
         */

        int abl2 = abl_grid_points_x * abl_grid_points_y,
            indexIntoAB[abl_grid_points_x][abl_grid_points_y],
            probePointCounter = -1;

        float eqnAMatrix[abl2 * 3], // "A" matrix of the linear system of equations
              eqnBVector[abl2],     // "B" vector of Z points
              mean = 0.0;

      #endif // AUTO_BED_LEVELING_LINEAR_GRID

      bool zig = abl_grid_points_y & 1; //always end at [RIGHT_PROBE_BED_POSITION, BACK_PROBE_BED_POSITION]

      for (uint8_t yCount = 0; yCount < abl_grid_points_y; yCount++) {
        float yBase = front_probe_bed_position + yGridSpacing * yCount;
        yProbe = floor(yBase + (yBase < 0 ? 0 : 0.5));

        int8_t xStart, xStop, xInc;

        if (zig) {
          xStart = 0;
          xStop = abl_grid_points_x;
          xInc = 1;
        }
        else {
          xStart = abl_grid_points_x - 1;
          xStop = -1;
          xInc = -1;
        }

        zig = !zig;

        for (int8_t xCount = xStart; xCount != xStop; xCount += xInc) {
          float xBase = left_probe_bed_position + xGridSpacing * xCount;
          xProbe = floor(xBase + (xBase < 0 ? 0 : 0.5));

          #if ENABLED(AUTO_BED_LEVELING_LINEAR_GRID)
            indexIntoAB[xCount][yCount] = ++probePointCounter;
          #endif

          #if IS_KINEMATIC
            // Avoid probing outside the round or hexagonal area
            float pos[XYZ] = { xProbe, yProbe, 0 };
            if (!position_is_reachable(pos, true)) continue;
          #endif

          measured_z = probe_pt(xProbe, yProbe, stow_probe_after_each, verbose_level);

          if (measured_z == NAN) {
            planner.abl_enabled = abl_should_reenable;
            return;
          }

          #if ENABLED(AUTO_BED_LEVELING_LINEAR_GRID)

            mean += measured_z;
            eqnBVector[probePointCounter] = measured_z;
            eqnAMatrix[probePointCounter + 0 * abl2] = xProbe;
            eqnAMatrix[probePointCounter + 1 * abl2] = yProbe;
            eqnAMatrix[probePointCounter + 2 * abl2] = 1;

          #elif ENABLED(AUTO_BED_LEVELING_NONLINEAR)

            bed_level_grid[xCount][yCount] = measured_z + zoffset;

          #endif

          idle();

        } //xProbe
      } //yProbe

    #elif ENABLED(AUTO_BED_LEVELING_3POINT)

      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("> 3-point Leveling");
      #endif

      // Probe at 3 arbitrary points
      vector_3 points[3] = {
        vector_3(ABL_PROBE_PT_1_X, ABL_PROBE_PT_1_Y, 0),
        vector_3(ABL_PROBE_PT_2_X, ABL_PROBE_PT_2_Y, 0),
        vector_3(ABL_PROBE_PT_3_X, ABL_PROBE_PT_3_Y, 0)
      };

      for (uint8_t i = 0; i < 3; ++i) {
        // Retain the last probe position
        xProbe = LOGICAL_X_POSITION(points[i].x);
        yProbe = LOGICAL_Y_POSITION(points[i].y);
        measured_z = points[i].z = probe_pt(xProbe, yProbe, stow_probe_after_each, verbose_level);
      }

      if (measured_z == NAN) {
        planner.abl_enabled = abl_should_reenable;
        return;
      }

      if (!dryrun) {
        vector_3 planeNormal = vector_3::cross(points[0] - points[1], points[2] - points[1]).get_normal();
        if (planeNormal.z < 0) {
          planeNormal.x *= -1;
          planeNormal.y *= -1;
          planeNormal.z *= -1;
        }
        planner.bed_level_matrix = matrix_3x3::create_look_at(planeNormal);

        // Can't re-enable (on error) until the new grid is written
        abl_should_reenable = false;
      }

    #endif // AUTO_BED_LEVELING_3POINT

    // Raise to _Z_CLEARANCE_DEPLOY_PROBE. Stow the probe.
    if (STOW_PROBE()) {
      planner.abl_enabled = abl_should_reenable;
      return;
    }

    //
    // Unless this is a dry run, auto bed leveling will
    // definitely be enabled after this point
    //

    // Restore state after probing
    clean_up_after_endstop_or_probe_move();

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) DEBUG_POS("> probing complete", current_position);
    #endif

    // Calculate leveling, print reports, correct the position
    #if ENABLED(AUTO_BED_LEVELING_NONLINEAR)

      if (!dryrun) extrapolate_unprobed_bed_level();
      print_bed_level();

    #elif ENABLED(AUTO_BED_LEVELING_LINEAR_GRID)

      // For LINEAR leveling calculate matrix, print reports, correct the position

      // solve lsq problem
      float plane_equation_coefficients[3];
      qr_solve(plane_equation_coefficients, abl2, 3, eqnAMatrix, eqnBVector);

      mean /= abl2;

      if (verbose_level) {
        SERIAL_PROTOCOLPGM("Eqn coefficients: a: ");
        SERIAL_PROTOCOL_F(plane_equation_coefficients[0], 8);
        SERIAL_PROTOCOLPGM(" b: ");
        SERIAL_PROTOCOL_F(plane_equation_coefficients[1], 8);
        SERIAL_PROTOCOLPGM(" d: ");
        SERIAL_PROTOCOL_F(plane_equation_coefficients[2], 8);
        SERIAL_EOL;
        if (verbose_level > 2) {
          SERIAL_PROTOCOLPGM("Mean of sampled points: ");
          SERIAL_PROTOCOL_F(mean, 8);
          SERIAL_EOL;
        }
      }

      // Create the matrix but don't correct the position yet
      if (!dryrun) {
        planner.bed_level_matrix = matrix_3x3::create_look_at(
          vector_3(-plane_equation_coefficients[0], -plane_equation_coefficients[1], 1)
        );
      }

      // Show the Topography map if enabled
      if (do_topography_map) {

        SERIAL_PROTOCOLLNPGM("\nBed Height Topography:\n"
                               "   +--- BACK --+\n"
                               "   |           |\n"
                               " L |    (+)    | R\n"
                               " E |           | I\n"
                               " F | (-) N (+) | G\n"
                               " T |           | H\n"
                               "   |    (-)    | T\n"
                               "   |           |\n"
                               "   O-- FRONT --+\n"
                               " (0,0)");

        float min_diff = 999;

        for (int8_t yy = abl_grid_points_y - 1; yy >= 0; yy--) {
          for (uint8_t xx = 0; xx < abl_grid_points_x; xx++) {
            int ind = indexIntoAB[xx][yy];
            float diff = eqnBVector[ind] - mean,
                  x_tmp = eqnAMatrix[ind + 0 * abl2],
                  y_tmp = eqnAMatrix[ind + 1 * abl2],
                  z_tmp = 0;

            apply_rotation_xyz(planner.bed_level_matrix, x_tmp, y_tmp, z_tmp);

            NOMORE(min_diff, eqnBVector[ind] - z_tmp);

            if (diff >= 0.0)
              SERIAL_PROTOCOLPGM(" +");   // Include + for column alignment
            else
              SERIAL_PROTOCOLCHAR(' ');
            SERIAL_PROTOCOL_F(diff, 5);
          } // xx
          SERIAL_EOL;
        } // yy
        SERIAL_EOL;

        if (verbose_level > 3) {
          SERIAL_PROTOCOLLNPGM("\nCorrected Bed Height vs. Bed Topology:");

          for (int8_t yy = abl_grid_points_y - 1; yy >= 0; yy--) {
            for (uint8_t xx = 0; xx < abl_grid_points_x; xx++) {
              int ind = indexIntoAB[xx][yy];
              float x_tmp = eqnAMatrix[ind + 0 * abl2],
                    y_tmp = eqnAMatrix[ind + 1 * abl2],
                    z_tmp = 0;

              apply_rotation_xyz(planner.bed_level_matrix, x_tmp, y_tmp, z_tmp);

              float diff = eqnBVector[ind] - z_tmp - min_diff;
              if (diff >= 0.0)
                SERIAL_PROTOCOLPGM(" +");
              // Include + for column alignment
              else
                SERIAL_PROTOCOLCHAR(' ');
              SERIAL_PROTOCOL_F(diff, 5);
            } // xx
            SERIAL_EOL;
          } // yy
          SERIAL_EOL;
        }
      } //do_topography_map

    #endif // AUTO_BED_LEVELING_LINEAR_GRID

    #if ENABLED(AUTO_BED_LEVELING_LINEAR)

      // For LINEAR and 3POINT leveling correct the current position

      if (verbose_level > 0)
        planner.bed_level_matrix.debug("\n\nBed Level Correction Matrix:");

      if (!dryrun) {
        //
        // Correct the current XYZ position based on the tilted plane.
        //

        // 1. Get the distance from the current position to the reference point.
        float x_dist = RAW_CURRENT_POSITION(X_AXIS) - X_TILT_FULCRUM,
              y_dist = RAW_CURRENT_POSITION(Y_AXIS) - Y_TILT_FULCRUM,
              z_real = RAW_CURRENT_POSITION(Z_AXIS),
              z_zero = 0;

        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("G29 uncorrected XYZ", current_position);
        #endif

        matrix_3x3 inverse = matrix_3x3::transpose(planner.bed_level_matrix);

        // 2. Apply the inverse matrix to the distance
        //    from the reference point to X, Y, and zero.
        apply_rotation_xyz(inverse, x_dist, y_dist, z_zero);

        // 3. Get the matrix-based corrected Z.
        //    (Even if not used, get it for comparison.)
        float new_z = z_real + z_zero;

        // 4. Use the last measured distance to the bed, if possible
        if ( NEAR(current_position[X_AXIS], xProbe - (X_PROBE_OFFSET_FROM_EXTRUDER))
          && NEAR(current_position[Y_AXIS], yProbe - (Y_PROBE_OFFSET_FROM_EXTRUDER))
        ) {
          float simple_z = z_real - (measured_z - (-zprobe_zoffset));
          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) {
              SERIAL_ECHOPAIR("Z from Probe:", simple_z);
              SERIAL_ECHOPAIR("  Matrix:", new_z);
              SERIAL_ECHOLNPAIR("  Discrepancy:", simple_z - new_z);
            }
          #endif
          new_z = simple_z;
        }

        // 5. The rotated XY and corrected Z are now current_position
        current_position[X_AXIS] = LOGICAL_X_POSITION(x_dist) + X_TILT_FULCRUM;
        current_position[Y_AXIS] = LOGICAL_Y_POSITION(y_dist) + Y_TILT_FULCRUM;
        current_position[Z_AXIS] = LOGICAL_Z_POSITION(new_z);

        SYNC_PLAN_POSITION_KINEMATIC();

        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("G29 corrected XYZ", current_position);
        #endif
      }

    #endif // AUTO_BED_LEVELING_LINEAR

    #ifdef Z_PROBE_END_SCRIPT
      #if ENABLED(DEBUG_LEVELING_FEATURE)
        if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPAIR("Z Probe End Script: ", Z_PROBE_END_SCRIPT);
      #endif
      enqueue_and_echo_commands_P(PSTR(Z_PROBE_END_SCRIPT));
      stepper.synchronize();
    #endif

    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) SERIAL_ECHOLNPGM("<<< gcode_G29");
    #endif

    report_current_position();

    KEEPALIVE_STATE(IN_HANDLER);

    // Auto Bed Leveling is complete! Enable if possible.
    planner.abl_enabled = dryrun ? abl_should_reenable : true;
  }

#endif // AUTO_BED_LEVELING_FEATURE

#if HAS_BED_PROBE

  /**
   * G30: Do a single Z probe at the current XY
   */
  inline void gcode_G30() {

    #if ENABLED(AUTO_BED_LEVELING_FEATURE)
      reset_bed_level();
    #endif

    setup_for_endstop_or_probe_move();

    // TODO: clear the leveling matrix or the planner will be set incorrectly
    float measured_z = probe_pt(current_position[X_AXIS] + X_PROBE_OFFSET_FROM_EXTRUDER,
                                current_position[Y_AXIS] + Y_PROBE_OFFSET_FROM_EXTRUDER,
                                true, 1);

    SERIAL_PROTOCOLPGM("Bed X: ");
    SERIAL_PROTOCOL(current_position[X_AXIS] + X_PROBE_OFFSET_FROM_EXTRUDER + 0.0001);
    SERIAL_PROTOCOLPGM(" Y: ");
    SERIAL_PROTOCOL(current_position[Y_AXIS] + Y_PROBE_OFFSET_FROM_EXTRUDER + 0.0001);
    SERIAL_PROTOCOLPGM(" Z: ");
    SERIAL_PROTOCOL(measured_z + 0.0001);
    SERIAL_EOL;

    clean_up_after_endstop_or_probe_move();

    report_current_position();
  }

  #if ENABLED(Z_PROBE_SLED)

    /**
     * G31: Deploy the Z probe
     */
    inline void gcode_G31() { DEPLOY_PROBE(); }

    /**
     * G32: Stow the Z probe
     */
    inline void gcode_G32() { STOW_PROBE(); }

  #endif // Z_PROBE_SLED

#endif // HAS_BED_PROBE

/**
 * G92: Set current position to given X Y Z E
 */
inline void gcode_G92() {
  bool didXYZ = false,
       didE = code_seen('E');

  if (!didE) stepper.synchronize();

  LOOP_XYZE(i) {
    if (code_seen(axis_codes[i])) {
      #if IS_SCARA
        current_position[i] = code_value_axis_units(i);
        if (i != E_AXIS) didXYZ = true;
      #else
        float p = current_position[i],
              v = code_value_axis_units(i);

        current_position[i] = v;

        if (i != E_AXIS) {
          didXYZ = true;
          position_shift[i] += v - p; // Offset the coordinate space
          update_software_endstops((AxisEnum)i);
        }
      #endif
    }
  }
  if (didXYZ)
    SYNC_PLAN_POSITION_KINEMATIC();
  else if (didE)
    sync_plan_position_e();

  report_current_position();
}

#if ENABLED(ULTIPANEL) || ENABLED(EMERGENCY_PARSER)

  /**
   * M0: Unconditional stop - Wait for user button press on LCD
   * M1: Conditional stop   - Wait for user button press on LCD
   */
  inline void gcode_M0_M1() {
    char* args = current_command_args;

    millis_t codenum = 0;
    bool hasP = false, hasS = false;
    if (code_seen('P')) {
      codenum = code_value_millis(); // milliseconds to wait
      hasP = codenum > 0;
    }
    if (code_seen('S')) {
      codenum = code_value_millis_from_seconds(); // seconds to wait
      hasS = codenum > 0;
    }

    #if ENABLED(ULTIPANEL)

      if (!hasP && !hasS && *args != '\0')
        lcd_setstatus(args, true);
      else {
        LCD_MESSAGEPGM(MSG_USERWAIT);
        #if ENABLED(LCD_PROGRESS_BAR) && PROGRESS_MSG_EXPIRE > 0
          dontExpireStatus();
        #endif
      }
      lcd_ignore_click();

    #else

      if (!hasP && !hasS && *args != '\0') {
        SERIAL_ECHO_START;
        SERIAL_ECHOLN(args);
      }

    #endif

    stepper.synchronize();
    refresh_cmd_timeout();

    #if ENABLED(ULTIPANEL)

      if (codenum > 0) {
        codenum += previous_cmd_ms;  // wait until this time for a click
        KEEPALIVE_STATE(PAUSED_FOR_USER);
        while (PENDING(millis(), codenum) && !lcd_clicked()) idle();
        lcd_ignore_click(false);
      }
      else if (lcd_detected()) {
        KEEPALIVE_STATE(PAUSED_FOR_USER);
        while (!lcd_clicked()) idle();
      }
      else return;

      if (IS_SD_PRINTING)
        LCD_MESSAGEPGM(MSG_RESUMING);
      else
        LCD_MESSAGEPGM(WELCOME_MSG);

    #else

      KEEPALIVE_STATE(PAUSED_FOR_USER);
      wait_for_user = true;

      if (codenum > 0) {
        codenum += previous_cmd_ms;  // wait until this time for an M108
        while (PENDING(millis(), codenum) && wait_for_user) idle();
      }
      else while (wait_for_user) idle();

      wait_for_user = false;

    #endif

    KEEPALIVE_STATE(IN_HANDLER);
  }

#endif // ULTIPANEL || EMERGENCY_PARSER

/**
 * M17: Enable power on all stepper motors
 */
inline void gcode_M17() {
  LCD_MESSAGEPGM(MSG_NO_MOVE);
  enable_all_steppers();
}

#if ENABLED(SDSUPPORT)

  /**
   * M20: List SD card to serial output
   */
  inline void gcode_M20() {
    SERIAL_PROTOCOLLNPGM(MSG_BEGIN_FILE_LIST);
    card.ls();
    SERIAL_PROTOCOLLNPGM(MSG_END_FILE_LIST);
  }

  /**
   * M21: Init SD Card
   */
  inline void gcode_M21() { card.initsd(); }

  /**
   * M22: Release SD Card
   */
  inline void gcode_M22() { card.release(); }

  /**
   * M23: Open a file
   */
  inline void gcode_M23() { card.openFile(current_command_args, true); }

  /**
   * M24: Start SD Print
   */
  inline void gcode_M24() {
    card.startFileprint();
    print_job_timer.start();
  }

  /**
   * M25: Pause SD Print
   */
  inline void gcode_M25() { card.pauseSDPrint(); }

  /**
   * M26: Set SD Card file index
   */
  inline void gcode_M26() {
    if (card.cardOK && code_seen('S'))
      card.setIndex(code_value_long());
  }

  /**
   * M27: Get SD Card status
   */
  inline void gcode_M27() { card.getStatus(); }

  /**
   * M28: Start SD Write
   */
  inline void gcode_M28() { card.openFile(current_command_args, false); }

  /**
   * M29: Stop SD Write
   * Processed in write to file routine above
   */
  inline void gcode_M29() {
    // card.saving = false;
  }

  /**
   * M30 <filename>: Delete SD Card file
   */
  inline void gcode_M30() {
    if (card.cardOK) {
      card.closefile();
      card.removeFile(current_command_args);
    }
  }

#endif // SDSUPPORT

/**
 * M31: Get the time since the start of SD Print (or last M109)
 */
inline void gcode_M31() {
  char buffer[21];
  duration_t elapsed = print_job_timer.duration();
  elapsed.toString(buffer);

  lcd_setstatus(buffer);

  SERIAL_ECHO_START;
  SERIAL_ECHOLNPAIR("Print time: ", buffer);

  thermalManager.autotempShutdown();
}

#if ENABLED(SDSUPPORT)

  /**
   * M32: Select file and start SD Print
   */
  inline void gcode_M32() {
    if (card.sdprinting)
      stepper.synchronize();

    char* namestartpos = strchr(current_command_args, '!');  // Find ! to indicate filename string start.
    if (!namestartpos)
      namestartpos = current_command_args; // Default name position, 4 letters after the M
    else
      namestartpos++; //to skip the '!'

    bool call_procedure = code_seen('P') && (seen_pointer < namestartpos);

    if (card.cardOK) {
      card.openFile(namestartpos, true, call_procedure);

      if (code_seen('S') && seen_pointer < namestartpos) // "S" (must occur _before_ the filename!)
        card.setIndex(code_value_long());

      card.startFileprint();

      // Procedure calls count as normal print time.
      if (!call_procedure) print_job_timer.start();
    }
  }

  #if ENABLED(LONG_FILENAME_HOST_SUPPORT)

    /**
     * M33: Get the long full path of a file or folder
     *
     * Parameters:
     *   <dospath> Case-insensitive DOS-style path to a file or folder
     *
     * Example:
     *   M33 miscel~1/armchair/armcha~1.gco
     *
     * Output:
     *   /Miscellaneous/Armchair/Armchair.gcode
     */
    inline void gcode_M33() {
      card.printLongPath(current_command_args);
    }

  #endif

  /**
   * M928: Start SD Write
   */
  inline void gcode_M928() {
    card.openLogFile(current_command_args);
  }

#endif // SDSUPPORT

/**
 * M42: Change pin status via GCode
 *
 *  P<pin>  Pin number (LED if omitted)
 *  S<byte> Pin status from 0 - 255
 */
inline void gcode_M42() {
  if (!code_seen('S')) return;

  int pin_status = code_value_int();
  if (pin_status < 0 || pin_status > 255) return;

  int pin_number = code_seen('P') ? code_value_int() : LED_PIN;
  if (pin_number < 0) return;

  for (uint8_t i = 0; i < COUNT(sensitive_pins); i++)
    if (pin_number == sensitive_pins[i]) {
      SERIAL_ERROR_START;
      SERIAL_ERRORLNPGM(MSG_ERR_PROTECTED_PIN);
      return;
    }

  pinMode(pin_number, OUTPUT);
  digitalWrite(pin_number, pin_status);
  analogWrite(pin_number, pin_status);

  #if FAN_COUNT > 0
    switch (pin_number) {
      #if HAS_FAN0
        case FAN_PIN: fanSpeeds[0] = pin_status; break;
      #endif
      #if HAS_FAN1
        case FAN1_PIN: fanSpeeds[1] = pin_status; break;
      #endif
      #if HAS_FAN2
        case FAN2_PIN: fanSpeeds[2] = pin_status; break;
      #endif
    }
  #endif
}

#if ENABLED(Z_MIN_PROBE_REPEATABILITY_TEST)

  /**
   * M48: Z probe repeatability measurement function.
   *
   * Usage:
   *   M48 <P#> <X#> <Y#> <V#> <E> <L#>
   *     P = Number of sampled points (4-50, default 10)
   *     X = Sample X position
   *     Y = Sample Y position
   *     V = Verbose level (0-4, default=1)
   *     E = Engage Z probe for each reading
   *     L = Number of legs of movement before probe
   *     S = Schizoid (Or Star if you prefer)
   *
   * This function assumes the bed has been homed.  Specifically, that a G28 command
   * as been issued prior to invoking the M48 Z probe repeatability measurement function.
   * Any information generated by a prior G29 Bed leveling command will be lost and need to be
   * regenerated.
   */
  inline void gcode_M48() {

    if (axis_unhomed_error(true, true, true)) return;

    int8_t verbose_level = code_seen('V') ? code_value_byte() : 1;
    if (verbose_level < 0 || verbose_level > 4) {
      SERIAL_PROTOCOLLNPGM("?Verbose Level not plausible (0-4).");
      return;
    }

    if (verbose_level > 0)
      SERIAL_PROTOCOLLNPGM("M48 Z-Probe Repeatability test");

    int8_t n_samples = code_seen('P') ? code_value_byte() : 10;
    if (n_samples < 4 || n_samples > 50) {
      SERIAL_PROTOCOLLNPGM("?Sample size not plausible (4-50).");
      return;
    }

    float  X_current = current_position[X_AXIS],
           Y_current = current_position[Y_AXIS];

    bool stow_probe_after_each = code_seen('E');

    float X_probe_location = code_seen('X') ? code_value_axis_units(X_AXIS) : X_current + X_PROBE_OFFSET_FROM_EXTRUDER;
    #if DISABLED(DELTA)
      if (X_probe_location < LOGICAL_X_POSITION(MIN_PROBE_X) || X_probe_location > LOGICAL_X_POSITION(MAX_PROBE_X)) {
        out_of_range_error(PSTR("X"));
        return;
      }
    #endif

    float Y_probe_location = code_seen('Y') ? code_value_axis_units(Y_AXIS) : Y_current + Y_PROBE_OFFSET_FROM_EXTRUDER;
    #if DISABLED(DELTA)
      if (Y_probe_location < LOGICAL_Y_POSITION(MIN_PROBE_Y) || Y_probe_location > LOGICAL_Y_POSITION(MAX_PROBE_Y)) {
        out_of_range_error(PSTR("Y"));
        return;
      }
    #else
      float pos[XYZ] = { X_probe_location, Y_probe_location, 0 };
      if (!position_is_reachable(pos, true)) {
        SERIAL_PROTOCOLLNPGM("? (X,Y) location outside of probeable radius.");
        return;
      }
    #endif

    bool seen_L = code_seen('L');
    uint8_t n_legs = seen_L ? code_value_byte() : 0;
    if (n_legs > 15) {
      SERIAL_PROTOCOLLNPGM("?Number of legs in movement not plausible (0-15).");
      return;
    }
    if (n_legs == 1) n_legs = 2;

    bool schizoid_flag = code_seen('S');
    if (schizoid_flag && !seen_L) n_legs = 7;

    /**
     * Now get everything to the specified probe point So we can safely do a
     * probe to get us close to the bed.  If the Z-Axis is far from the bed,
     * we don't want to use that as a starting point for each probe.
     */
    if (verbose_level > 2)
      SERIAL_PROTOCOLLNPGM("Positioning the probe...");

    // Disable bed level correction in M48 because we want the raw data when we probe
    #if ENABLED(AUTO_BED_LEVELING_FEATURE)
      reset_bed_level();
    #endif

    setup_for_endstop_or_probe_move();

    // Move to the first point, deploy, and probe
    probe_pt(X_probe_location, Y_probe_location, stow_probe_after_each, verbose_level);

    randomSeed(millis());

    double mean = 0, sigma = 0, sample_set[n_samples];
    for (uint8_t n = 0; n < n_samples; n++) {
      if (n_legs) {
        int dir = (random(0, 10) > 5.0) ? -1 : 1;  // clockwise or counter clockwise
        float angle = random(0.0, 360.0),
              radius = random(
                #if ENABLED(DELTA)
                  DELTA_PROBEABLE_RADIUS / 8, DELTA_PROBEABLE_RADIUS / 3
                #else
                  5, X_MAX_LENGTH / 8
                #endif
              );

        if (verbose_level > 3) {
          SERIAL_ECHOPAIR("Starting radius: ", radius);
          SERIAL_ECHOPAIR("   angle: ", angle);
          SERIAL_ECHOPGM(" Direction: ");
          if (dir > 0) SERIAL_ECHOPGM("Counter-");
          SERIAL_ECHOLNPGM("Clockwise");
        }

        for (uint8_t l = 0; l < n_legs - 1; l++) {
          double delta_angle;

          if (schizoid_flag)
            // The points of a 5 point star are 72 degrees apart.  We need to
            // skip a point and go to the next one on the star.
            delta_angle = dir * 2.0 * 72.0;

          else
            // If we do this line, we are just trying to move further
            // around the circle.
            delta_angle = dir * (float) random(25, 45);

          angle += delta_angle;

          while (angle > 360.0)   // We probably do not need to keep the angle between 0 and 2*PI, but the
            angle -= 360.0;       // Arduino documentation says the trig functions should not be given values
          while (angle < 0.0)     // outside of this range.   It looks like they behave correctly with
            angle += 360.0;       // numbers outside of the range, but just to be safe we clamp them.

          X_current = X_probe_location - (X_PROBE_OFFSET_FROM_EXTRUDER) + cos(RADIANS(angle)) * radius;
          Y_current = Y_probe_location - (Y_PROBE_OFFSET_FROM_EXTRUDER) + sin(RADIANS(angle)) * radius;

          #if DISABLED(DELTA)
            X_current = constrain(X_current, X_MIN_POS, X_MAX_POS);
            Y_current = constrain(Y_current, Y_MIN_POS, Y_MAX_POS);
          #else
            // If we have gone out too far, we can do a simple fix and scale the numbers
            // back in closer to the origin.
            while (HYPOT(X_current, Y_current) > DELTA_PROBEABLE_RADIUS) {
              X_current /= 1.25;
              Y_current /= 1.25;
              if (verbose_level > 3) {
                SERIAL_ECHOPAIR("Pulling point towards center:", X_current);
                SERIAL_ECHOLNPAIR(", ", Y_current);
              }
            }
          #endif
          if (verbose_level > 3) {
            SERIAL_PROTOCOLPGM("Going to:");
            SERIAL_ECHOPAIR(" X", X_current);
            SERIAL_ECHOPAIR(" Y", Y_current);
            SERIAL_ECHOLNPAIR(" Z", current_position[Z_AXIS]);
          }
          do_blocking_move_to_xy(X_current, Y_current);
        } // n_legs loop
      } // n_legs

      // Probe a single point
      sample_set[n] = probe_pt(X_probe_location, Y_probe_location, stow_probe_after_each, verbose_level);

      /**
       * Get the current mean for the data points we have so far
       */
      double sum = 0.0;
      for (uint8_t j = 0; j <= n; j++) sum += sample_set[j];
      mean = sum / (n + 1);

      /**
       * Now, use that mean to calculate the standard deviation for the
       * data points we have so far
       */
      sum = 0.0;
      for (uint8_t j = 0; j <= n; j++)
        sum += sq(sample_set[j] - mean);

      sigma = sqrt(sum / (n + 1));
      if (verbose_level > 0) {
        if (verbose_level > 1) {
          SERIAL_PROTOCOL(n + 1);
          SERIAL_PROTOCOLPGM(" of ");
          SERIAL_PROTOCOL((int)n_samples);
          SERIAL_PROTOCOLPGM("   z: ");
          SERIAL_PROTOCOL_F(current_position[Z_AXIS], 6);
          if (verbose_level > 2) {
            SERIAL_PROTOCOLPGM(" mean: ");
            SERIAL_PROTOCOL_F(mean, 6);
            SERIAL_PROTOCOLPGM("   sigma: ");
            SERIAL_PROTOCOL_F(sigma, 6);
          }
        }
        SERIAL_EOL;
      }

    } // End of probe loop

    if (STOW_PROBE()) return;

    if (verbose_level > 0) {
      SERIAL_PROTOCOLPGM("Mean: ");
      SERIAL_PROTOCOL_F(mean, 6);
      SERIAL_EOL;
    }

    SERIAL_PROTOCOLPGM("Standard Deviation: ");
    SERIAL_PROTOCOL_F(sigma, 6);
    SERIAL_EOL; SERIAL_EOL;

    clean_up_after_endstop_or_probe_move();

    report_current_position();
  }

#endif // Z_MIN_PROBE_REPEATABILITY_TEST

/**
 * M75: Start print timer
 */
inline void gcode_M75() { print_job_timer.start(); }

/**
 * M76: Pause print timer
 */
inline void gcode_M76() { print_job_timer.pause(); }

/**
 * M77: Stop print timer
 */
inline void gcode_M77() { print_job_timer.stop(); }

#if ENABLED(PRINTCOUNTER)
  /**
   * M78: Show print statistics
   */
  inline void gcode_M78() {
    // "M78 S78" will reset the statistics
    if (code_seen('S') && code_value_int() == 78)
      print_job_timer.initStats();
    else
      print_job_timer.showStats();
  }
#endif

/**
 * M104: Set hot end temperature
 */
inline void gcode_M104() {
  if (get_target_extruder_from_command(104)) return;
  if (DEBUGGING(DRYRUN)) return;

  #if ENABLED(SINGLENOZZLE)
    if (target_extruder != active_extruder) return;
  #endif

  if (code_seen('S')) {
    thermalManager.setTargetHotend(code_value_temp_abs(), target_extruder);
    #if ENABLED(DUAL_X_CARRIAGE)
      if (dual_x_carriage_mode == DXC_DUPLICATION_MODE && target_extruder == 0)
        thermalManager.setTargetHotend(code_value_temp_abs() == 0.0 ? 0.0 : code_value_temp_abs() + duplicate_extruder_temp_offset, 1);
    #endif

    #if ENABLED(PRINTJOB_TIMER_AUTOSTART)
      /**
       * Stop the timer at the end of print, starting is managed by
       * 'heat and wait' M109.
       * We use half EXTRUDE_MINTEMP here to allow nozzles to be put into hot
       * stand by mode, for instance in a dual extruder setup, without affecting
       * the running print timer.
       */
      if (code_value_temp_abs() <= (EXTRUDE_MINTEMP)/2) {
        print_job_timer.stop();
        LCD_MESSAGEPGM(WELCOME_MSG);
      }
    #endif

    if (code_value_temp_abs() > thermalManager.degHotend(target_extruder)) LCD_MESSAGEPGM(MSG_HEATING);
  }
}

#if HAS_TEMP_HOTEND || HAS_TEMP_BED

  void print_heaterstates() {
    #if HAS_TEMP_HOTEND
      SERIAL_PROTOCOLPGM(" T:");
      SERIAL_PROTOCOL_F(thermalManager.degHotend(target_extruder), 1);
      SERIAL_PROTOCOLPGM(" /");
      SERIAL_PROTOCOL_F(thermalManager.degTargetHotend(target_extruder), 1);
      #if ENABLED(SHOW_TEMP_ADC_VALUES)
        SERIAL_PROTOCOLPAIR(" (", thermalManager.current_temperature_raw[target_extruder] / OVERSAMPLENR);
        SERIAL_CHAR(')');
      #endif
    #endif
    #if HAS_TEMP_BED
      SERIAL_PROTOCOLPGM(" B:");
      SERIAL_PROTOCOL_F(thermalManager.degBed(), 1);
      SERIAL_PROTOCOLPGM(" /");
      SERIAL_PROTOCOL_F(thermalManager.degTargetBed(), 1);
      #if ENABLED(SHOW_TEMP_ADC_VALUES)
        SERIAL_PROTOCOLPAIR(" (", thermalManager.current_temperature_bed_raw / OVERSAMPLENR);
        SERIAL_CHAR(')');
      #endif
    #endif
    #if HOTENDS > 1
      HOTEND_LOOP() {
        SERIAL_PROTOCOLPAIR(" T", e);
        SERIAL_PROTOCOLCHAR(':');
        SERIAL_PROTOCOL_F(thermalManager.degHotend(e), 1);
        SERIAL_PROTOCOLPGM(" /");
        SERIAL_PROTOCOL_F(thermalManager.degTargetHotend(e), 1);
        #if ENABLED(SHOW_TEMP_ADC_VALUES)
          SERIAL_PROTOCOLPAIR(" (", thermalManager.current_temperature_raw[e] / OVERSAMPLENR);
          SERIAL_CHAR(')');
        #endif
      }
    #endif
    SERIAL_PROTOCOLPGM(" @:");
    SERIAL_PROTOCOL(thermalManager.getHeaterPower(target_extruder));
    #if HAS_TEMP_BED
      SERIAL_PROTOCOLPGM(" B@:");
      SERIAL_PROTOCOL(thermalManager.getHeaterPower(-1));
    #endif
    #if HOTENDS > 1
      HOTEND_LOOP() {
        SERIAL_PROTOCOLPAIR(" @", e);
        SERIAL_PROTOCOLCHAR(':');
        SERIAL_PROTOCOL(thermalManager.getHeaterPower(e));
      }
    #endif
  }
#endif

/**
 * M105: Read hot end and bed temperature
 */
inline void gcode_M105() {
  if (get_target_extruder_from_command(105)) return;

  #if HAS_TEMP_HOTEND || HAS_TEMP_BED
    SERIAL_PROTOCOLPGM(MSG_OK);
    print_heaterstates();
  #else // !HAS_TEMP_HOTEND && !HAS_TEMP_BED
    SERIAL_ERROR_START;
    SERIAL_ERRORLNPGM(MSG_ERR_NO_THERMISTORS);
  #endif

  SERIAL_EOL;
}

#if FAN_COUNT > 0

  /**
   * M106: Set Fan Speed
   *
   *  S<int>   Speed between 0-255
   *  P<index> Fan index, if more than one fan
   */
  inline void gcode_M106() {
    uint16_t s = code_seen('S') ? code_value_ushort() : 255,
             p = code_seen('P') ? code_value_ushort() : 0;
    NOMORE(s, 255);
    if (p < FAN_COUNT) fanSpeeds[p] = s;
  }

  /**
   * M107: Fan Off
   */
  inline void gcode_M107() {
    uint16_t p = code_seen('P') ? code_value_ushort() : 0;
    if (p < FAN_COUNT) fanSpeeds[p] = 0;
  }

#endif // FAN_COUNT > 0

#if DISABLED(EMERGENCY_PARSER)

  /**
   * M108: Stop the waiting for heaters in M109, M190, M303. Does not affect the target temperature.
   */
  inline void gcode_M108() { wait_for_heatup = false; }


  /**
   * M112: Emergency Stop
   */
  inline void gcode_M112() { kill(PSTR(MSG_KILLED)); }


  /**
   * M410: Quickstop - Abort all planned moves
   *
   * This will stop the carriages mid-move, so most likely they
   * will be out of sync with the stepper position after this.
   */
  inline void gcode_M410() { quickstop_stepper(); }

#endif

  #ifndef MIN_COOLING_SLOPE_DEG
    #define MIN_COOLING_SLOPE_DEG 1.50
  #endif
  #ifndef MIN_COOLING_SLOPE_TIME
    #define MIN_COOLING_SLOPE_TIME 60
  #endif

/**
 * M109: Sxxx Wait for extruder(s) to reach temperature. Waits only when heating.
 *       Rxxx Wait for extruder(s) to reach temperature. Waits when heating and cooling.
 */
inline void gcode_M109() {

  if (get_target_extruder_from_command(109)) return;
  if (DEBUGGING(DRYRUN)) return;

  #if ENABLED(SINGLENOZZLE)
    if (target_extruder != active_extruder) return;
  #endif

  bool no_wait_for_cooling = code_seen('S');
  if (no_wait_for_cooling || code_seen('R')) {
    thermalManager.setTargetHotend(code_value_temp_abs(), target_extruder);
    #if ENABLED(DUAL_X_CARRIAGE)
      if (dual_x_carriage_mode == DXC_DUPLICATION_MODE && target_extruder == 0)
        thermalManager.setTargetHotend(code_value_temp_abs() == 0.0 ? 0.0 : code_value_temp_abs() + duplicate_extruder_temp_offset, 1);
    #endif

    #if ENABLED(PRINTJOB_TIMER_AUTOSTART)
      /**
       * We use half EXTRUDE_MINTEMP here to allow nozzles to be put into hot
       * stand by mode, for instance in a dual extruder setup, without affecting
       * the running print timer.
       */
      if (code_value_temp_abs() <= (EXTRUDE_MINTEMP)/2) {
        print_job_timer.stop();
        LCD_MESSAGEPGM(WELCOME_MSG);
      }
      /**
       * We do not check if the timer is already running because this check will
       * be done for us inside the Stopwatch::start() method thus a running timer
       * will not restart.
       */
      else print_job_timer.start();
    #endif

    if (thermalManager.isHeatingHotend(target_extruder)) LCD_MESSAGEPGM(MSG_HEATING);
  }

  #if ENABLED(AUTOTEMP)
    planner.autotemp_M109();
  #endif

  #if TEMP_RESIDENCY_TIME > 0
    millis_t residency_start_ms = 0;
    // Loop until the temperature has stabilized
    #define TEMP_CONDITIONS (!residency_start_ms || PENDING(now, residency_start_ms + (TEMP_RESIDENCY_TIME) * 1000UL))
  #else
    // Loop until the temperature is very close target
    #define TEMP_CONDITIONS (wants_to_cool ? thermalManager.isCoolingHotend(target_extruder) : thermalManager.isHeatingHotend(target_extruder))
  #endif //TEMP_RESIDENCY_TIME > 0

  float theTarget = -1.0, old_temp = 9999.0;
  bool wants_to_cool = false;
  wait_for_heatup = true;
  millis_t now, next_temp_ms = 0, next_cool_check_ms = 0;

  KEEPALIVE_STATE(NOT_BUSY);

  do {
    // Target temperature might be changed during the loop
    if (theTarget != thermalManager.degTargetHotend(target_extruder)) {
      wants_to_cool = thermalManager.isCoolingHotend(target_extruder);
      theTarget = thermalManager.degTargetHotend(target_extruder);

      // Exit if S<lower>, continue if S<higher>, R<lower>, or R<higher>
      if (no_wait_for_cooling && wants_to_cool) break;
    }

    now = millis();
    if (ELAPSED(now, next_temp_ms)) { //Print temp & remaining time every 1s while waiting
      next_temp_ms = now + 1000UL;
      print_heaterstates();
      #if TEMP_RESIDENCY_TIME > 0
        SERIAL_PROTOCOLPGM(" W:");
        if (residency_start_ms) {
          long rem = (((TEMP_RESIDENCY_TIME) * 1000UL) - (now - residency_start_ms)) / 1000UL;
          SERIAL_PROTOCOLLN(rem);
        }
        else {
          SERIAL_PROTOCOLLNPGM("?");
        }
      #else
        SERIAL_EOL;
      #endif
    }

    idle();
    refresh_cmd_timeout(); // to prevent stepper_inactive_time from running out

    float temp = thermalManager.degHotend(target_extruder);

    #if TEMP_RESIDENCY_TIME > 0

      float temp_diff = fabs(theTarget - temp);

      if (!residency_start_ms) {
        // Start the TEMP_RESIDENCY_TIME timer when we reach target temp for the first time.
        if (temp_diff < TEMP_WINDOW) residency_start_ms = now;
      }
      else if (temp_diff > TEMP_HYSTERESIS) {
        // Restart the timer whenever the temperature falls outside the hysteresis.
        residency_start_ms = now;
      }

    #endif //TEMP_RESIDENCY_TIME > 0

    // Prevent a wait-forever situation if R is misused i.e. M109 R0
    if (wants_to_cool) {
      // break after MIN_COOLING_SLOPE_TIME seconds
      // if the temperature did not drop at least MIN_COOLING_SLOPE_DEG
      if (!next_cool_check_ms || ELAPSED(now, next_cool_check_ms)) {
        if (old_temp - temp < MIN_COOLING_SLOPE_DEG) break;
        next_cool_check_ms = now + 1000UL * MIN_COOLING_SLOPE_TIME;
        old_temp = temp;
      }
    }

  } while (wait_for_heatup && TEMP_CONDITIONS);

  if (wait_for_heatup) LCD_MESSAGEPGM(MSG_HEATING_COMPLETE);

  KEEPALIVE_STATE(IN_HANDLER);
}

#if HAS_TEMP_BED

  #ifndef MIN_COOLING_SLOPE_DEG_BED
    #define MIN_COOLING_SLOPE_DEG_BED 1.50
  #endif
  #ifndef MIN_COOLING_SLOPE_TIME_BED
    #define MIN_COOLING_SLOPE_TIME_BED 60
  #endif

  /**
   * M190: Sxxx Wait for bed current temp to reach target temp. Waits only when heating
   *       Rxxx Wait for bed current temp to reach target temp. Waits when heating and cooling
   */
  inline void gcode_M190() {
    if (DEBUGGING(DRYRUN)) return;

    LCD_MESSAGEPGM(MSG_BED_HEATING);
    bool no_wait_for_cooling = code_seen('S');
    if (no_wait_for_cooling || code_seen('R')) {
      thermalManager.setTargetBed(code_value_temp_abs());
      #if ENABLED(PRINTJOB_TIMER_AUTOSTART)
        if (code_value_temp_abs() > BED_MINTEMP) {
          /**
          * We start the timer when 'heating and waiting' command arrives, LCD
          * functions never wait. Cooling down managed by extruders.
          *
          * We do not check if the timer is already running because this check will
          * be done for us inside the Stopwatch::start() method thus a running timer
          * will not restart.
          */
          print_job_timer.start();
        }
      #endif
    }

    #if TEMP_BED_RESIDENCY_TIME > 0
      millis_t residency_start_ms = 0;
      // Loop until the temperature has stabilized
      #define TEMP_BED_CONDITIONS (!residency_start_ms || PENDING(now, residency_start_ms + (TEMP_BED_RESIDENCY_TIME) * 1000UL))
    #else
      // Loop until the temperature is very close target
      #define TEMP_BED_CONDITIONS (wants_to_cool ? thermalManager.isCoolingBed() : thermalManager.isHeatingBed())
    #endif //TEMP_BED_RESIDENCY_TIME > 0

    float theTarget = -1.0, old_temp = 9999.0;
    bool wants_to_cool = false;
    wait_for_heatup = true;
    millis_t now, next_temp_ms = 0, next_cool_check_ms = 0;

    KEEPALIVE_STATE(NOT_BUSY);

    target_extruder = active_extruder; // for print_heaterstates

    do {
      // Target temperature might be changed during the loop
      if (theTarget != thermalManager.degTargetBed()) {
        wants_to_cool = thermalManager.isCoolingBed();
        theTarget = thermalManager.degTargetBed();

        // Exit if S<lower>, continue if S<higher>, R<lower>, or R<higher>
        if (no_wait_for_cooling && wants_to_cool) break;
      }

      now = millis();
      if (ELAPSED(now, next_temp_ms)) { //Print Temp Reading every 1 second while heating up.
        next_temp_ms = now + 1000UL;
        print_heaterstates();
        #if TEMP_BED_RESIDENCY_TIME > 0
          SERIAL_PROTOCOLPGM(" W:");
          if (residency_start_ms) {
            long rem = (((TEMP_BED_RESIDENCY_TIME) * 1000UL) - (now - residency_start_ms)) / 1000UL;
            SERIAL_PROTOCOLLN(rem);
          }
          else {
            SERIAL_PROTOCOLLNPGM("?");
          }
        #else
          SERIAL_EOL;
        #endif
      }

      idle();
      refresh_cmd_timeout(); // to prevent stepper_inactive_time from running out

      float temp = thermalManager.degBed();

      #if TEMP_BED_RESIDENCY_TIME > 0

        float temp_diff = fabs(theTarget - temp);

        if (!residency_start_ms) {
          // Start the TEMP_BED_RESIDENCY_TIME timer when we reach target temp for the first time.
          if (temp_diff < TEMP_BED_WINDOW) residency_start_ms = now;
        }
        else if (temp_diff > TEMP_BED_HYSTERESIS) {
          // Restart the timer whenever the temperature falls outside the hysteresis.
          residency_start_ms = now;
        }

      #endif //TEMP_BED_RESIDENCY_TIME > 0

      // Prevent a wait-forever situation if R is misused i.e. M190 R0
      if (wants_to_cool) {
        // break after MIN_COOLING_SLOPE_TIME_BED seconds
        // if the temperature did not drop at least MIN_COOLING_SLOPE_DEG_BED
        if (!next_cool_check_ms || ELAPSED(now, next_cool_check_ms)) {
          if (old_temp - temp < MIN_COOLING_SLOPE_DEG_BED) break;
          next_cool_check_ms = now + 1000UL * MIN_COOLING_SLOPE_TIME_BED;
          old_temp = temp;
        }
      }

    } while (wait_for_heatup && TEMP_BED_CONDITIONS);

    if (wait_for_heatup) LCD_MESSAGEPGM(MSG_BED_DONE);
    KEEPALIVE_STATE(IN_HANDLER);
  }

#endif // HAS_TEMP_BED

/**
 * M110: Set Current Line Number
 */
inline void gcode_M110() {
  if (code_seen('N')) gcode_N = code_value_long();
}

/**
 * M111: Set the debug level
 */
inline void gcode_M111() {
  marlin_debug_flags = code_seen('S') ? code_value_byte() : (uint8_t) DEBUG_NONE;

  const static char str_debug_1[] PROGMEM = MSG_DEBUG_ECHO;
  const static char str_debug_2[] PROGMEM = MSG_DEBUG_INFO;
  const static char str_debug_4[] PROGMEM = MSG_DEBUG_ERRORS;
  const static char str_debug_8[] PROGMEM = MSG_DEBUG_DRYRUN;
  const static char str_debug_16[] PROGMEM = MSG_DEBUG_COMMUNICATION;
  #if ENABLED(DEBUG_LEVELING_FEATURE)
    const static char str_debug_32[] PROGMEM = MSG_DEBUG_LEVELING;
  #endif

  const static char* const debug_strings[] PROGMEM = {
    str_debug_1, str_debug_2, str_debug_4, str_debug_8, str_debug_16,
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      str_debug_32
    #endif
  };

  SERIAL_ECHO_START;
  SERIAL_ECHOPGM(MSG_DEBUG_PREFIX);
  if (marlin_debug_flags) {
    uint8_t comma = 0;
    for (uint8_t i = 0; i < COUNT(debug_strings); i++) {
      if (TEST(marlin_debug_flags, i)) {
        if (comma++) SERIAL_CHAR(',');
        serialprintPGM((char*)pgm_read_word(&(debug_strings[i])));
      }
    }
  }
  else {
    SERIAL_ECHOPGM(MSG_DEBUG_OFF);
  }
  SERIAL_EOL;
}

#if ENABLED(HOST_KEEPALIVE_FEATURE)

  /**
   * M113: Get or set Host Keepalive interval (0 to disable)
   *
   *   S<seconds> Optional. Set the keepalive interval.
   */
  inline void gcode_M113() {
    if (code_seen('S')) {
      host_keepalive_interval = code_value_byte();
      NOMORE(host_keepalive_interval, 60);
    }
    else {
      SERIAL_ECHO_START;
      SERIAL_ECHOLNPAIR("M113 S", (unsigned long)host_keepalive_interval);
    }
  }

#endif

#if ENABLED(BARICUDA)

  #if HAS_HEATER_1
    /**
     * M126: Heater 1 valve open
     */
    inline void gcode_M126() { baricuda_valve_pressure = code_seen('S') ? code_value_byte() : 255; }
    /**
     * M127: Heater 1 valve close
     */
    inline void gcode_M127() { baricuda_valve_pressure = 0; }
  #endif

  #if HAS_HEATER_2
    /**
     * M128: Heater 2 valve open
     */
    inline void gcode_M128() { baricuda_e_to_p_pressure = code_seen('S') ? code_value_byte() : 255; }
    /**
     * M129: Heater 2 valve close
     */
    inline void gcode_M129() { baricuda_e_to_p_pressure = 0; }
  #endif

#endif //BARICUDA

/**
 * M140: Set bed temperature
 */
inline void gcode_M140() {
  if (DEBUGGING(DRYRUN)) return;
  if (code_seen('S')) thermalManager.setTargetBed(code_value_temp_abs());
}

#if ENABLED(ULTIPANEL)

  /**
   * M145: Set the heatup state for a material in the LCD menu
   *   S<material> (0=PLA, 1=ABS)
   *   H<hotend temp>
   *   B<bed temp>
   *   F<fan speed>
   */
  inline void gcode_M145() {
    int8_t material = code_seen('S') ? (int8_t)code_value_int() : 0;
    if (material < 0 || material > 1) {
      SERIAL_ERROR_START;
      SERIAL_ERRORLNPGM(MSG_ERR_MATERIAL_INDEX);
    }
    else {
      int v;
      switch (material) {
        case 0:
          if (code_seen('H')) {
            v = code_value_int();
            preheatHotendTemp1 = constrain(v, EXTRUDE_MINTEMP, HEATER_0_MAXTEMP - 15);
          }
          if (code_seen('F')) {
            v = code_value_int();
            preheatFanSpeed1 = constrain(v, 0, 255);
          }
          #if TEMP_SENSOR_BED != 0
            if (code_seen('B')) {
              v = code_value_int();
              preheatBedTemp1 = constrain(v, BED_MINTEMP, BED_MAXTEMP - 15);
            }
          #endif
          break;
        case 1:
          if (code_seen('H')) {
            v = code_value_int();
            preheatHotendTemp2 = constrain(v, EXTRUDE_MINTEMP, HEATER_0_MAXTEMP - 15);
          }
          if (code_seen('F')) {
            v = code_value_int();
            preheatFanSpeed2 = constrain(v, 0, 255);
          }
          #if TEMP_SENSOR_BED != 0
            if (code_seen('B')) {
              v = code_value_int();
              preheatBedTemp2 = constrain(v, BED_MINTEMP, BED_MAXTEMP - 15);
            }
          #endif
          break;
      }
    }
  }

#endif // ULTIPANEL

#if ENABLED(TEMPERATURE_UNITS_SUPPORT)
  /**
   * M149: Set temperature units
   */
  inline void gcode_M149() {
    if (code_seen('C')) {
      set_input_temp_units(TEMPUNIT_C);
    } else if (code_seen('K')) {
      set_input_temp_units(TEMPUNIT_K);
    } else if (code_seen('F')) {
      set_input_temp_units(TEMPUNIT_F);
    }
  }
#endif

#if HAS_POWER_SWITCH

  /**
   * M80: Turn on Power Supply
   */
  inline void gcode_M80() {
    OUT_WRITE(PS_ON_PIN, PS_ON_AWAKE); //GND

    /**
     * If you have a switch on suicide pin, this is useful
     * if you want to start another print with suicide feature after
     * a print without suicide...
     */
    #if HAS_SUICIDE
      OUT_WRITE(SUICIDE_PIN, HIGH);
    #endif

    #if ENABLED(ULTIPANEL)
      powersupply = true;
      LCD_MESSAGEPGM(WELCOME_MSG);
      lcd_update();
    #endif
  }

#endif // HAS_POWER_SWITCH

/**
 * M81: Turn off Power, including Power Supply, if there is one.
 *
 *      This code should ALWAYS be available for EMERGENCY SHUTDOWN!
 */
inline void gcode_M81() {
  thermalManager.disable_all_heaters();
  stepper.finish_and_disable();
  #if FAN_COUNT > 0
    #if FAN_COUNT > 1
      for (uint8_t i = 0; i < FAN_COUNT; i++) fanSpeeds[i] = 0;
    #else
      fanSpeeds[0] = 0;
    #endif
  #endif
  delay(1000); // Wait 1 second before switching off
  #if HAS_SUICIDE
    stepper.synchronize();
    suicide();
  #elif HAS_POWER_SWITCH
    OUT_WRITE(PS_ON_PIN, PS_ON_ASLEEP);
  #endif
  #if ENABLED(ULTIPANEL)
    #if HAS_POWER_SWITCH
      powersupply = false;
    #endif
    LCD_MESSAGEPGM(MACHINE_NAME " " MSG_OFF ".");
    lcd_update();
  #endif
}

/**
 * M82: Set E codes absolute (default)
 */
inline void gcode_M82() { axis_relative_modes[E_AXIS] = false; }

/**
 * M83: Set E codes relative while in Absolute Coordinates (G90) mode
 */
inline void gcode_M83() { axis_relative_modes[E_AXIS] = true; }

/**
 * M18, M84: Disable all stepper motors
 */
inline void gcode_M18_M84() {
  if (code_seen('S')) {
    stepper_inactive_time = code_value_millis_from_seconds();
  }
  else {
    bool all_axis = !((code_seen('X')) || (code_seen('Y')) || (code_seen('Z')) || (code_seen('E')));
    if (all_axis) {
      stepper.finish_and_disable();
    }
    else {
      stepper.synchronize();
      if (code_seen('X')) disable_x();
      if (code_seen('Y')) disable_y();
      if (code_seen('Z')) disable_z();
      #if ((E0_ENABLE_PIN != X_ENABLE_PIN) && (E1_ENABLE_PIN != Y_ENABLE_PIN)) // Only enable on boards that have seperate ENABLE_PINS
        if (code_seen('E')) {
          disable_e0();
          disable_e1();
          disable_e2();
          disable_e3();
        }
      #endif
    }
  }
}

/**
 * M85: Set inactivity shutdown timer with parameter S<seconds>. To disable set zero (default)
 */
inline void gcode_M85() {
  if (code_seen('S')) max_inactive_time = code_value_millis_from_seconds();
}

/**
 * M92: Set axis steps-per-unit for one or more axes, X, Y, Z, and E.
 *      (Follows the same syntax as G92)
 */
inline void gcode_M92() {
  LOOP_XYZE(i) {
    if (code_seen(axis_codes[i])) {
      if (i == E_AXIS) {
        float value = code_value_per_axis_unit(i);
        if (value < 20.0) {
          float factor = planner.axis_steps_per_mm[i] / value; // increase e constants if M92 E14 is given for netfab.
          planner.max_e_jerk *= factor;
          planner.max_feedrate_mm_s[i] *= factor;
          planner.max_acceleration_steps_per_s2[i] *= factor;
        }
        planner.axis_steps_per_mm[i] = value;
      }
      else {
        planner.axis_steps_per_mm[i] = code_value_per_axis_unit(i);
      }
    }
  }
  planner.refresh_positioning();
}

/**
 * Output the current position to serial
 */
static void report_current_position() {
  SERIAL_PROTOCOLPGM("X:");
  SERIAL_PROTOCOL(current_position[X_AXIS]);
  SERIAL_PROTOCOLPGM(" Y:");
  SERIAL_PROTOCOL(current_position[Y_AXIS]);
  SERIAL_PROTOCOLPGM(" Z:");
  SERIAL_PROTOCOL(current_position[Z_AXIS]);
  SERIAL_PROTOCOLPGM(" E:");
  SERIAL_PROTOCOL(current_position[E_AXIS]);

  stepper.report_positions();

  #if IS_SCARA
    SERIAL_PROTOCOLPAIR("SCARA Theta:", stepper.get_axis_position_mm(A_AXIS));
    SERIAL_PROTOCOLLNPAIR("   Psi+Theta:", stepper.get_axis_position_mm(B_AXIS));
    SERIAL_EOL;
  #endif
}

/**
 * M114: Output current position to serial port
 */
inline void gcode_M114() { report_current_position(); }

/**
 * M115: Capabilities string
 */
inline void gcode_M115() {
  SERIAL_PROTOCOLPGM(MSG_M115_REPORT);
}

/**
 * M117: Set LCD Status Message
 */
inline void gcode_M117() {
  lcd_setstatus(current_command_args);
}

/**
 * M119: Output endstop states to serial output
 */
inline void gcode_M119() { endstops.M119(); }

/**
 * M120: Enable endstops and set non-homing endstop state to "enabled"
 */
inline void gcode_M120() { endstops.enable_globally(true); }

/**
 * M121: Disable endstops and set non-homing endstop state to "disabled"
 */
inline void gcode_M121() { endstops.enable_globally(false); }

#if ENABLED(BLINKM)

  /**
   * M150: Set Status LED Color - Use R-U-B for R-G-B
   */
  inline void gcode_M150() {
    SendColors(
      code_seen('R') ? code_value_byte() : 0,
      code_seen('U') ? code_value_byte() : 0,
      code_seen('B') ? code_value_byte() : 0
    );
  }

#endif // BLINKM

#if ENABLED(EXPERIMENTAL_I2CBUS)

  /**
   * M155: Send data to a I2C slave device
   *
   * This is a PoC, the formating and arguments for the GCODE will
   * change to be more compatible, the current proposal is:
   *
   *  M155 A<slave device address base 10> ; Sets the I2C slave address the data will be sent to
   *
   *  M155 B<byte-1 value in base 10>
   *  M155 B<byte-2 value in base 10>
   *  M155 B<byte-3 value in base 10>
   *
   *  M155 S1 ; Send the buffered data and reset the buffer
   *  M155 R1 ; Reset the buffer without sending data
   *
   */
  inline void gcode_M155() {
    // Set the target address
    if (code_seen('A')) i2c.address(code_value_byte());

    // Add a new byte to the buffer
    if (code_seen('B')) i2c.addbyte(code_value_byte());

    // Flush the buffer to the bus
    if (code_seen('S')) i2c.send();

    // Reset and rewind the buffer
    else if (code_seen('R')) i2c.reset();
  }

  /**
   * M156: Request X bytes from I2C slave device
   *
   * Usage: M156 A<slave device address base 10> B<number of bytes>
   */
  inline void gcode_M156() {
    if (code_seen('A')) i2c.address(code_value_byte());

    uint8_t bytes = code_seen('B') ? code_value_byte() : 1;

    if (i2c.addr && bytes && bytes <= TWIBUS_BUFFER_SIZE) {
      i2c.relay(bytes);
    }
    else {
      SERIAL_ERROR_START;
      SERIAL_ERRORLN("Bad i2c request");
    }
  }

#endif // EXPERIMENTAL_I2CBUS

/**
 * M200: Set filament diameter and set E axis units to cubic units
 *
 *    T<extruder> - Optional extruder number. Current extruder if omitted.
 *    D<linear> - Diameter of the filament. Use "D0" to switch back to linear units on the E axis.
 */
inline void gcode_M200() {

  if (get_target_extruder_from_command(200)) return;

  if (code_seen('D')) {
    // setting any extruder filament size disables volumetric on the assumption that
    // slicers either generate in extruder values as cubic mm or as as filament feeds
    // for all extruders
    volumetric_enabled = (code_value_linear_units() != 0.0);
    if (volumetric_enabled) {
      filament_size[target_extruder] = code_value_linear_units();
      // make sure all extruders have some sane value for the filament size
      for (uint8_t i = 0; i < COUNT(filament_size); i++)
        if (! filament_size[i]) filament_size[i] = DEFAULT_NOMINAL_FILAMENT_DIA;
    }
  }
  else {
    //reserved for setting filament diameter via UFID or filament measuring device
    return;
  }
  calculate_volumetric_multipliers();
}

/**
 * M201: Set max acceleration in units/s^2 for print moves (M201 X1000 Y1000)
 */
inline void gcode_M201() {
  LOOP_XYZE(i) {
    if (code_seen(axis_codes[i])) {
      planner.max_acceleration_mm_per_s2[i] = code_value_axis_units(i);
    }
  }
  // steps per sq second need to be updated to agree with the units per sq second (as they are what is used in the planner)
  planner.reset_acceleration_rates();
}

#if 0 // Not used for Sprinter/grbl gen6
  inline void gcode_M202() {
    LOOP_XYZE(i) {
      if (code_seen(axis_codes[i])) axis_travel_steps_per_sqr_second[i] = code_value_axis_units(i) * planner.axis_steps_per_mm[i];
    }
  }
#endif


/**
 * M203: Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in units/sec
 */
inline void gcode_M203() {
  LOOP_XYZE(i)
    if (code_seen(axis_codes[i]))
      planner.max_feedrate_mm_s[i] = code_value_axis_units(i);
}

/**
 * M204: Set Accelerations in units/sec^2 (M204 P1200 R3000 T3000)
 *
 *    P = Printing moves
 *    R = Retract only (no X, Y, Z) moves
 *    T = Travel (non printing) moves
 *
 *  Also sets minimum segment time in ms (B20000) to prevent buffer under-runs and M20 minimum feedrate
 */
inline void gcode_M204() {
  if (code_seen('S')) {  // Kept for legacy compatibility. Should NOT BE USED for new developments.
    planner.travel_acceleration = planner.acceleration = code_value_linear_units();
    SERIAL_ECHOLNPAIR("Setting Print and Travel Acceleration: ", planner.acceleration);
  }
  if (code_seen('P')) {
    planner.acceleration = code_value_linear_units();
    SERIAL_ECHOLNPAIR("Setting Print Acceleration: ", planner.acceleration);
  }
  if (code_seen('R')) {
    planner.retract_acceleration = code_value_linear_units();
    SERIAL_ECHOLNPAIR("Setting Retract Acceleration: ", planner.retract_acceleration);
  }
  if (code_seen('T')) {
    planner.travel_acceleration = code_value_linear_units();
    SERIAL_ECHOLNPAIR("Setting Travel Acceleration: ", planner.travel_acceleration);
  }
}

/**
 * M205: Set Advanced Settings
 *
 *    S = Min Feed Rate (units/s)
 *    T = Min Travel Feed Rate (units/s)
 *    B = Min Segment Time (µs)
 *    X = Max XY Jerk (units/sec^2)
 *    Z = Max Z Jerk (units/sec^2)
 *    E = Max E Jerk (units/sec^2)
 */
inline void gcode_M205() {
  if (code_seen('S')) planner.min_feedrate_mm_s = code_value_linear_units();
  if (code_seen('T')) planner.min_travel_feedrate_mm_s = code_value_linear_units();
  if (code_seen('B')) planner.min_segment_time = code_value_millis();
  if (code_seen('X')) planner.max_xy_jerk = code_value_linear_units();
  if (code_seen('Z')) planner.max_z_jerk = code_value_axis_units(Z_AXIS);
  if (code_seen('E')) planner.max_e_jerk = code_value_axis_units(E_AXIS);
}

/**
 * M206: Set Additional Homing Offset (X Y Z). SCARA aliases T=X, P=Y
 */
inline void gcode_M206() {
  LOOP_XYZ(i)
    if (code_seen(axis_codes[i]))
      set_home_offset((AxisEnum)i, code_value_axis_units(i));

  #if ENABLED(MORGAN_SCARA)
    if (code_seen('T')) set_home_offset(A_AXIS, code_value_axis_units(A_AXIS)); // Theta
    if (code_seen('P')) set_home_offset(B_AXIS, code_value_axis_units(B_AXIS)); // Psi
  #endif

  SYNC_PLAN_POSITION_KINEMATIC();
  report_current_position();
}

#if ENABLED(DELTA)
  /**
   * M665: Set delta configurations
   *
   *    L = diagonal rod
   *    R = delta radius
   *    S = segments per second
   *    A = Alpha (Tower 1) diagonal rod trim
   *    B = Beta (Tower 2) diagonal rod trim
   *    C = Gamma (Tower 3) diagonal rod trim
   */
  inline void gcode_M665() {
    if (code_seen('L')) delta_diagonal_rod = code_value_linear_units();
    if (code_seen('R')) delta_radius = code_value_linear_units();
    if (code_seen('S')) delta_segments_per_second = code_value_float();
    if (code_seen('A')) delta_diagonal_rod_trim_tower_1 = code_value_linear_units();
    if (code_seen('B')) delta_diagonal_rod_trim_tower_2 = code_value_linear_units();
    if (code_seen('C')) delta_diagonal_rod_trim_tower_3 = code_value_linear_units();
    recalc_delta_settings(delta_radius, delta_diagonal_rod);
  }
  /**
   * M666: Set delta endstop adjustment
   */
  inline void gcode_M666() {
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOLNPGM(">>> gcode_M666");
      }
    #endif
    LOOP_XYZ(i) {
      if (code_seen(axis_codes[i])) {
        endstop_adj[i] = code_value_axis_units(i);
        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) {
            SERIAL_ECHOPAIR("endstop_adj[", axis_codes[i]);
            SERIAL_ECHOLNPAIR("] = ", endstop_adj[i]);
          }
        #endif
      }
    }
    #if ENABLED(DEBUG_LEVELING_FEATURE)
      if (DEBUGGING(LEVELING)) {
        SERIAL_ECHOLNPGM("<<< gcode_M666");
      }
    #endif
  }

#elif ENABLED(Z_DUAL_ENDSTOPS) // !DELTA && ENABLED(Z_DUAL_ENDSTOPS)

  /**
   * M666: For Z Dual Endstop setup, set z axis offset to the z2 axis.
   */
  inline void gcode_M666() {
    if (code_seen('Z')) z_endstop_adj = code_value_axis_units(Z_AXIS);
    SERIAL_ECHOLNPAIR("Z Endstop Adjustment set to (mm):", z_endstop_adj);
  }

#endif // !DELTA && Z_DUAL_ENDSTOPS

#if ENABLED(FWRETRACT)

  /**
   * M207: Set firmware retraction values
   *
   *   S[+units]    retract_length
   *   W[+units]    retract_length_swap (multi-extruder)
   *   F[units/min] retract_feedrate_mm_s
   *   Z[units]     retract_zlift
   */
  inline void gcode_M207() {
    if (code_seen('S')) retract_length = code_value_axis_units(E_AXIS);
    if (code_seen('F')) retract_feedrate_mm_s = MMM_TO_MMS(code_value_axis_units(E_AXIS));
    if (code_seen('Z')) retract_zlift = code_value_axis_units(Z_AXIS);
    #if EXTRUDERS > 1
      if (code_seen('W')) retract_length_swap = code_value_axis_units(E_AXIS);
    #endif
  }

  /**
   * M208: Set firmware un-retraction values
   *
   *   S[+units]    retract_recover_length (in addition to M207 S*)
   *   W[+units]    retract_recover_length_swap (multi-extruder)
   *   F[units/min] retract_recover_feedrate_mm_s
   */
  inline void gcode_M208() {
    if (code_seen('S')) retract_recover_length = code_value_axis_units(E_AXIS);
    if (code_seen('F')) retract_recover_feedrate_mm_s = MMM_TO_MMS(code_value_axis_units(E_AXIS));
    #if EXTRUDERS > 1
      if (code_seen('W')) retract_recover_length_swap = code_value_axis_units(E_AXIS);
    #endif
  }

  /**
   * M209: Enable automatic retract (M209 S1)
   *       detect if the slicer did not support G10/11: every normal extrude-only move will be classified as retract depending on the direction.
   */
  inline void gcode_M209() {
    if (code_seen('S')) {
      autoretract_enabled = code_value_bool();
      for (int i = 0; i < EXTRUDERS; i++) retracted[i] = false;
    }
  }

#endif // FWRETRACT

/**
 * M211: Enable, Disable, and/or Report software endstops
 *
 * Usage: M211 S1 to enable, M211 S0 to disable, M211 alone for report
 */
inline void gcode_M211() {
  SERIAL_ECHO_START;
  #if ENABLED(min_software_endstops) || ENABLED(max_software_endstops)
    if (code_seen('S')) soft_endstops_enabled = code_value_bool();
  #endif
  #if ENABLED(min_software_endstops) || ENABLED(max_software_endstops)
    SERIAL_ECHOPGM(MSG_SOFT_ENDSTOPS);
    serialprintPGM(soft_endstops_enabled ? PSTR(MSG_ON) : PSTR(MSG_OFF));
  #else
    SERIAL_ECHOPGM(MSG_SOFT_ENDSTOPS);
    SERIAL_ECHOPGM(MSG_OFF);
  #endif
  SERIAL_ECHOPGM(MSG_SOFT_MIN);
  SERIAL_ECHOPAIR(    MSG_X, soft_endstop_min[X_AXIS]);
  SERIAL_ECHOPAIR(" " MSG_Y, soft_endstop_min[Y_AXIS]);
  SERIAL_ECHOPAIR(" " MSG_Z, soft_endstop_min[Z_AXIS]);
  SERIAL_ECHOPGM(MSG_SOFT_MAX);
  SERIAL_ECHOPAIR(    MSG_X, soft_endstop_max[X_AXIS]);
  SERIAL_ECHOPAIR(" " MSG_Y, soft_endstop_max[Y_AXIS]);
  SERIAL_ECHOLNPAIR(" " MSG_Z, soft_endstop_max[Z_AXIS]);
}

#if HOTENDS > 1

  /**
   * M218 - set hotend offset (in linear units)
   *
   *   T<tool>
   *   X<xoffset>
   *   Y<yoffset>
   *   Z<zoffset> - Available with DUAL_X_CARRIAGE and SWITCHING_EXTRUDER
   */
  inline void gcode_M218() {
    if (get_target_extruder_from_command(218)) return;

    if (code_seen('X')) hotend_offset[X_AXIS][target_extruder] = code_value_axis_units(X_AXIS);
    if (code_seen('Y')) hotend_offset[Y_AXIS][target_extruder] = code_value_axis_units(Y_AXIS);

    #if ENABLED(DUAL_X_CARRIAGE) || ENABLED(SWITCHING_EXTRUDER)
      if (code_seen('Z')) hotend_offset[Z_AXIS][target_extruder] = code_value_axis_units(Z_AXIS);
    #endif

    SERIAL_ECHO_START;
    SERIAL_ECHOPGM(MSG_HOTEND_OFFSET);
    HOTEND_LOOP() {
      SERIAL_CHAR(' ');
      SERIAL_ECHO(hotend_offset[X_AXIS][e]);
      SERIAL_CHAR(',');
      SERIAL_ECHO(hotend_offset[Y_AXIS][e]);
      #if ENABLED(DUAL_X_CARRIAGE) || ENABLED(SWITCHING_EXTRUDER)
        SERIAL_CHAR(',');
        SERIAL_ECHO(hotend_offset[Z_AXIS][e]);
      #endif
    }
    SERIAL_EOL;
  }

#endif // HOTENDS > 1

/**
 * M220: Set speed percentage factor, aka "Feed Rate" (M220 S95)
 */
inline void gcode_M220() {
  if (code_seen('S')) feedrate_percentage = code_value_int();
}

/**
 * M221: Set extrusion percentage (M221 T0 S95)
 */
inline void gcode_M221() {
  if (get_target_extruder_from_command(221)) return;
  if (code_seen('S'))
    flow_percentage[target_extruder] = code_value_int();
}

/**
 * M226: Wait until the specified pin reaches the state required (M226 P<pin> S<state>)
 */
inline void gcode_M226() {
  if (code_seen('P')) {
    int pin_number = code_value_int();
    int pin_state = code_seen('S') ? code_value_int() : -1; // required pin state - default is inverted

    if (pin_state >= -1 && pin_state <= 1) {

      for (uint8_t i = 0; i < COUNT(sensitive_pins); i++) {
        if (sensitive_pins[i] == pin_number) {
          pin_number = -1;
          break;
        }
      }

      if (pin_number > -1) {
        int target = LOW;

        stepper.synchronize();

        pinMode(pin_number, INPUT);

        switch (pin_state) {
          case 1:
            target = HIGH;
            break;

          case 0:
            target = LOW;
            break;

          case -1:
            target = !digitalRead(pin_number);
            break;
        }

        while (digitalRead(pin_number) != target) idle();

      } // pin_number > -1
    } // pin_state -1 0 1
  } // code_seen('P')
}

#if HAS_SERVOS

  /**
   * M280: Get or set servo position. P<index> [S<angle>]
   */
  inline void gcode_M280() {
    if (!code_seen('P')) return;
    int servo_index = code_value_int();
    if (servo_index >= 0 && servo_index < NUM_SERVOS) {
      if (code_seen('S'))
        MOVE_SERVO(servo_index, code_value_int());
      else {
        SERIAL_ECHO_START;
        SERIAL_ECHOPAIR(" Servo ", servo_index);
        SERIAL_ECHOLNPAIR(": ", servo[servo_index].read());
      }
    }
    else {
      SERIAL_ERROR_START;
      SERIAL_ECHOPAIR("Servo ", servo_index);
      SERIAL_ECHOLNPGM(" out of range");
    }
  }

#endif // HAS_SERVOS

#if HAS_BUZZER

  /**
   * M300: Play beep sound S<frequency Hz> P<duration ms>
   */
  inline void gcode_M300() {
    uint16_t const frequency = code_seen('S') ? code_value_ushort() : 260;
    uint16_t duration = code_seen('P') ? code_value_ushort() : 1000;

    // Limits the tone duration to 0-5 seconds.
    NOMORE(duration, 5000);

    BUZZ(duration, frequency);
  }

#endif // HAS_BUZZER

#if ENABLED(PIDTEMP)

  /**
   * M301: Set PID parameters P I D (and optionally C, L)
   *
   *   P[float] Kp term
   *   I[float] Ki term (unscaled)
   *   D[float] Kd term (unscaled)
   *
   * With PID_EXTRUSION_SCALING:
   *
   *   C[float] Kc term
   *   L[float] LPQ length
   */
  inline void gcode_M301() {

    // multi-extruder PID patch: M301 updates or prints a single extruder's PID values
    // default behaviour (omitting E parameter) is to update for extruder 0 only
    int e = code_seen('E') ? code_value_int() : 0; // extruder being updated

    if (e < HOTENDS) { // catch bad input value
      if (code_seen('P')) PID_PARAM(Kp, e) = code_value_float();
      if (code_seen('I')) PID_PARAM(Ki, e) = scalePID_i(code_value_float());
      if (code_seen('D')) PID_PARAM(Kd, e) = scalePID_d(code_value_float());
      #if ENABLED(PID_EXTRUSION_SCALING)
        if (code_seen('C')) PID_PARAM(Kc, e) = code_value_float();
        if (code_seen('L')) lpq_len = code_value_float();
        NOMORE(lpq_len, LPQ_MAX_LEN);
      #endif

      thermalManager.updatePID();
      SERIAL_ECHO_START;
      #if ENABLED(PID_PARAMS_PER_HOTEND)
        SERIAL_ECHOPAIR(" e:", e); // specify extruder in serial output
      #endif // PID_PARAMS_PER_HOTEND
      SERIAL_ECHOPAIR(" p:", PID_PARAM(Kp, e));
      SERIAL_ECHOPAIR(" i:", unscalePID_i(PID_PARAM(Ki, e)));
      SERIAL_ECHOPAIR(" d:", unscalePID_d(PID_PARAM(Kd, e)));
      #if ENABLED(PID_EXTRUSION_SCALING)
        //Kc does not have scaling applied above, or in resetting defaults
        SERIAL_ECHOPAIR(" c:", PID_PARAM(Kc, e));
      #endif
      SERIAL_EOL;
    }
    else {
      SERIAL_ERROR_START;
      SERIAL_ERRORLN(MSG_INVALID_EXTRUDER);
    }
  }

#endif // PIDTEMP

#if ENABLED(PIDTEMPBED)

  inline void gcode_M304() {
    if (code_seen('P')) thermalManager.bedKp = code_value_float();
    if (code_seen('I')) thermalManager.bedKi = scalePID_i(code_value_float());
    if (code_seen('D')) thermalManager.bedKd = scalePID_d(code_value_float());

    thermalManager.updatePID();

    SERIAL_ECHO_START;
    SERIAL_ECHOPAIR(" p:", thermalManager.bedKp);
    SERIAL_ECHOPAIR(" i:", unscalePID_i(thermalManager.bedKi));
    SERIAL_ECHOLNPAIR(" d:", unscalePID_d(thermalManager.bedKd));
  }

#endif // PIDTEMPBED

#if defined(CHDK) || HAS_PHOTOGRAPH

  /**
   * M240: Trigger a camera by emulating a Canon RC-1
   *       See http://www.doc-diy.net/photo/rc-1_hacked/
   */
  inline void gcode_M240() {
    #ifdef CHDK

      OUT_WRITE(CHDK, HIGH);
      chdkHigh = millis();
      chdkActive = true;

    #elif HAS_PHOTOGRAPH

      const uint8_t NUM_PULSES = 16;
      const float PULSE_LENGTH = 0.01524;
      for (int i = 0; i < NUM_PULSES; i++) {
        WRITE(PHOTOGRAPH_PIN, HIGH);
        _delay_ms(PULSE_LENGTH);
        WRITE(PHOTOGRAPH_PIN, LOW);
        _delay_ms(PULSE_LENGTH);
      }
      delay(7.33);
      for (int i = 0; i < NUM_PULSES; i++) {
        WRITE(PHOTOGRAPH_PIN, HIGH);
        _delay_ms(PULSE_LENGTH);
        WRITE(PHOTOGRAPH_PIN, LOW);
        _delay_ms(PULSE_LENGTH);
      }

    #endif // !CHDK && HAS_PHOTOGRAPH
  }

#endif // CHDK || PHOTOGRAPH_PIN

#if HAS_LCD_CONTRAST

  /**
   * M250: Read and optionally set the LCD contrast
   */
  inline void gcode_M250() {
    if (code_seen('C')) set_lcd_contrast(code_value_int());
    SERIAL_PROTOCOLPGM("lcd contrast value: ");
    SERIAL_PROTOCOL(lcd_contrast);
    SERIAL_EOL;
  }

#endif // HAS_LCD_CONTRAST

#if ENABLED(PREVENT_COLD_EXTRUSION)

  /**
   * M302: Allow cold extrudes, or set the minimum extrude temperature
   *
   *       S<temperature> sets the minimum extrude temperature
   *       P<bool> enables (1) or disables (0) cold extrusion
   *
   *  Examples:
   *
   *       M302         ; report current cold extrusion state
   *       M302 P0      ; enable cold extrusion checking
   *       M302 P1      ; disables cold extrusion checking
   *       M302 S0      ; always allow extrusion (disables checking)
   *       M302 S170    ; only allow extrusion above 170
   *       M302 S170 P1 ; set min extrude temp to 170 but leave disabled
   */
  inline void gcode_M302() {
    bool seen_S = code_seen('S');
    if (seen_S) {
      thermalManager.extrude_min_temp = code_value_temp_abs();
      thermalManager.allow_cold_extrude = (thermalManager.extrude_min_temp == 0);
    }

    if (code_seen('P'))
      thermalManager.allow_cold_extrude = (thermalManager.extrude_min_temp == 0) || code_value_bool();
    else if (!seen_S) {
      // Report current state
      SERIAL_ECHO_START;
      SERIAL_ECHOPAIR("Cold extrudes are ", (thermalManager.allow_cold_extrude ? "en" : "dis"));
      SERIAL_ECHOPAIR("abled (min temp ", int(thermalManager.extrude_min_temp + 0.5));
      SERIAL_ECHOLNPGM("C)");
    }
  }

#endif // PREVENT_COLD_EXTRUSION

/**
 * M303: PID relay autotune
 *
 *       S<temperature> sets the target temperature. (default 150C)
 *       E<extruder> (-1 for the bed) (default 0)
 *       C<cycles>
 *       U<bool> with a non-zero value will apply the result to current settings
 */
inline void gcode_M303() {
  #if HAS_PID_HEATING
    int e = code_seen('E') ? code_value_int() : 0;
    int c = code_seen('C') ? code_value_int() : 5;
    bool u = code_seen('U') && code_value_bool();

    float temp = code_seen('S') ? code_value_temp_abs() : (e < 0 ? 70.0 : 150.0);

    if (e >= 0 && e < HOTENDS)
      target_extruder = e;

    KEEPALIVE_STATE(NOT_BUSY); // don't send "busy: processing" messages during autotune output

    thermalManager.PID_autotune(temp, e, c, u);

    KEEPALIVE_STATE(IN_HANDLER);
  #else
    SERIAL_ERROR_START;
    SERIAL_ERRORLNPGM(MSG_ERR_M303_DISABLED);
  #endif
}

#if ENABLED(MORGAN_SCARA)

  bool SCARA_move_to_cal(uint8_t delta_a, uint8_t delta_b) {
    if (IsRunning()) {
      forward_kinematics_SCARA(delta_a, delta_b);
      destination[X_AXIS] = LOGICAL_X_POSITION(cartes[X_AXIS]);
      destination[Y_AXIS] = LOGICAL_Y_POSITION(cartes[Y_AXIS]);
      destination[Z_AXIS] = current_position[Z_AXIS];
      prepare_move_to_destination();
      return true;
    }
    return false;
  }

  /**
   * M360: SCARA calibration: Move to cal-position ThetaA (0 deg calibration)
   */
  inline bool gcode_M360() {
    SERIAL_ECHOLNPGM(" Cal: Theta 0");
    return SCARA_move_to_cal(0, 120);
  }

  /**
   * M361: SCARA calibration: Move to cal-position ThetaB (90 deg calibration - steps per degree)
   */
  inline bool gcode_M361() {
    SERIAL_ECHOLNPGM(" Cal: Theta 90");
    return SCARA_move_to_cal(90, 130);
  }

  /**
   * M362: SCARA calibration: Move to cal-position PsiA (0 deg calibration)
   */
  inline bool gcode_M362() {
    SERIAL_ECHOLNPGM(" Cal: Psi 0");
    return SCARA_move_to_cal(60, 180);
  }

  /**
   * M363: SCARA calibration: Move to cal-position PsiB (90 deg calibration - steps per degree)
   */
  inline bool gcode_M363() {
    SERIAL_ECHOLNPGM(" Cal: Psi 90");
    return SCARA_move_to_cal(50, 90);
  }

  /**
   * M364: SCARA calibration: Move to cal-position PSIC (90 deg to Theta calibration position)
   */
  inline bool gcode_M364() {
    SERIAL_ECHOLNPGM(" Cal: Theta-Psi 90");
    return SCARA_move_to_cal(45, 135);
  }

#endif // SCARA

#if ENABLED(EXT_SOLENOID)

  void enable_solenoid(uint8_t num) {
    switch (num) {
      case 0:
        OUT_WRITE(SOL0_PIN, HIGH);
        break;
        #if HAS_SOLENOID_1
          case 1:
            OUT_WRITE(SOL1_PIN, HIGH);
            break;
        #endif
        #if HAS_SOLENOID_2
          case 2:
            OUT_WRITE(SOL2_PIN, HIGH);
            break;
        #endif
        #if HAS_SOLENOID_3
          case 3:
            OUT_WRITE(SOL3_PIN, HIGH);
            break;
        #endif
      default:
        SERIAL_ECHO_START;
        SERIAL_ECHOLNPGM(MSG_INVALID_SOLENOID);
        break;
    }
  }

  void enable_solenoid_on_active_extruder() { enable_solenoid(active_extruder); }

  void disable_all_solenoids() {
    OUT_WRITE(SOL0_PIN, LOW);
    OUT_WRITE(SOL1_PIN, LOW);
    OUT_WRITE(SOL2_PIN, LOW);
    OUT_WRITE(SOL3_PIN, LOW);
  }

  /**
   * M380: Enable solenoid on the active extruder
   */
  inline void gcode_M380() { enable_solenoid_on_active_extruder(); }

  /**
   * M381: Disable all solenoids
   */
  inline void gcode_M381() { disable_all_solenoids(); }

#endif // EXT_SOLENOID

/**
 * M400: Finish all moves
 */
inline void gcode_M400() { stepper.synchronize(); }

#if HAS_BED_PROBE

  /**
   * M401: Engage Z Servo endstop if available
   */
  inline void gcode_M401() { DEPLOY_PROBE(); }

  /**
   * M402: Retract Z Servo endstop if enabled
   */
  inline void gcode_M402() { STOW_PROBE(); }

#endif // HAS_BED_PROBE

#if ENABLED(FILAMENT_WIDTH_SENSOR)

  /**
   * M404: Display or set (in current units) the nominal filament width (3mm, 1.75mm ) W<3.0>
   */
  inline void gcode_M404() {
    if (code_seen('W')) {
      filament_width_nominal = code_value_linear_units();
    }
    else {
      SERIAL_PROTOCOLPGM("Filament dia (nominal mm):");
      SERIAL_PROTOCOLLN(filament_width_nominal);
    }
  }

  /**
   * M405: Turn on filament sensor for control
   */
  inline void gcode_M405() {
    // This is technically a linear measurement, but since it's quantized to centimeters and is a different unit than
    // everything else, it uses code_value_int() instead of code_value_linear_units().
    if (code_seen('D')) meas_delay_cm = code_value_int();
    NOMORE(meas_delay_cm, MAX_MEASUREMENT_DELAY);

    if (filwidth_delay_index[1] == -1) { // Initialize the ring buffer if not done since startup
      int temp_ratio = thermalManager.widthFil_to_size_ratio();

      for (uint8_t i = 0; i < COUNT(measurement_delay); ++i)
        measurement_delay[i] = temp_ratio - 100;  // Subtract 100 to scale within a signed byte

      filwidth_delay_index[0] = filwidth_delay_index[1] = 0;
    }

    filament_sensor = true;

    //SERIAL_PROTOCOLPGM("Filament dia (measured mm):");
    //SERIAL_PROTOCOL(filament_width_meas);
    //SERIAL_PROTOCOLPGM("Extrusion ratio(%):");
    //SERIAL_PROTOCOL(flow_percentage[active_extruder]);
  }

  /**
   * M406: Turn off filament sensor for control
   */
  inline void gcode_M406() { filament_sensor = false; }

  /**
   * M407: Get measured filament diameter on serial output
   */
  inline void gcode_M407() {
    SERIAL_PROTOCOLPGM("Filament dia (measured mm):");
    SERIAL_PROTOCOLLN(filament_width_meas);
  }

#endif // FILAMENT_WIDTH_SENSOR

void quickstop_stepper() {
  stepper.quick_stop();
  stepper.synchronize();
  set_current_from_steppers_for_axis(ALL_AXES);
  SYNC_PLAN_POSITION_KINEMATIC();
}

#if ENABLED(MESH_BED_LEVELING)

  /**
   * M420: Enable/Disable Mesh Bed Leveling
   */
  inline void gcode_M420() { if (code_seen('S')) mbl.set_has_mesh(code_value_bool()); }

  /**
   * M421: Set a single Mesh Bed Leveling Z coordinate
   * Use either 'M421 X<linear> Y<linear> Z<linear>' or 'M421 I<xindex> J<yindex> Z<linear>'
   */
  inline void gcode_M421() {
    int8_t px = 0, py = 0;
    float z = 0;
    bool hasX, hasY, hasZ, hasI, hasJ;
    if ((hasX = code_seen('X'))) px = mbl.probe_index_x(code_value_axis_units(X_AXIS));
    if ((hasY = code_seen('Y'))) py = mbl.probe_index_y(code_value_axis_units(Y_AXIS));
    if ((hasI = code_seen('I'))) px = code_value_axis_units(X_AXIS);
    if ((hasJ = code_seen('J'))) py = code_value_axis_units(Y_AXIS);
    if ((hasZ = code_seen('Z'))) z = code_value_axis_units(Z_AXIS);

    if (hasX && hasY && hasZ) {

      if (px >= 0 && py >= 0)
        mbl.set_z(px, py, z);
      else {
        SERIAL_ERROR_START;
        SERIAL_ERRORLNPGM(MSG_ERR_MESH_XY);
      }
    }
    else if (hasI && hasJ && hasZ) {
      if (px >= 0 && px < MESH_NUM_X_POINTS && py >= 0 && py < MESH_NUM_Y_POINTS)
        mbl.set_z(px, py, z);
      else {
        SERIAL_ERROR_START;
        SERIAL_ERRORLNPGM(MSG_ERR_MESH_XY);
      }
    }
    else {
      SERIAL_ERROR_START;
      SERIAL_ERRORLNPGM(MSG_ERR_M421_PARAMETERS);
    }
  }

#endif

/**
 * M428: Set home_offset based on the distance between the
 *       current_position and the nearest "reference point."
 *       If an axis is past center its endstop position
 *       is the reference-point. Otherwise it uses 0. This allows
 *       the Z offset to be set near the bed when using a max endstop.
 *
 *       M428 can't be used more than 2cm away from 0 or an endstop.
 *
 *       Use M206 to set these values directly.
 */
inline void gcode_M428() {
  bool err = false;
  LOOP_XYZ(i) {
    if (axis_homed[i]) {
      float base = (current_position[i] > (soft_endstop_min[i] + soft_endstop_max[i]) * 0.5) ? base_home_pos(i) : 0,
            diff = current_position[i] - LOGICAL_POSITION(base, i);
      if (diff > -20 && diff < 20) {
        set_home_offset((AxisEnum)i, home_offset[i] - diff);
      }
      else {
        SERIAL_ERROR_START;
        SERIAL_ERRORLNPGM(MSG_ERR_M428_TOO_FAR);
        LCD_ALERTMESSAGEPGM("Err: Too far!");
        BUZZ(200, 40);
        err = true;
        break;
      }
    }
  }

  if (!err) {
    SYNC_PLAN_POSITION_KINEMATIC();
    report_current_position();
    LCD_MESSAGEPGM(MSG_HOME_OFFSETS_APPLIED);
    BUZZ(200, 659);
    BUZZ(200, 698);
  }
}

/**
 * M500: Store settings in EEPROM
 */
inline void gcode_M500() {
  Config_StoreSettings();
}

/**
 * M501: Read settings from EEPROM
 */
inline void gcode_M501() {
  Config_RetrieveSettings();
}

/**
 * M502: Revert to default settings
 */
inline void gcode_M502() {
  Config_ResetDefault();
}

/**
 * M503: print settings currently in memory
 */
inline void gcode_M503() {
  Config_PrintSettings(code_seen('S') && !code_value_bool());
}

#if ENABLED(ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)

  /**
   * M540: Set whether SD card print should abort on endstop hit (M540 S<0|1>)
   */
  inline void gcode_M540() {
    if (code_seen('S')) stepper.abort_on_endstop_hit = code_value_bool();
  }

#endif // ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED

#if HAS_BED_PROBE

  inline void gcode_M851() {

    SERIAL_ECHO_START;
    SERIAL_ECHOPGM(MSG_ZPROBE_ZOFFSET);
    SERIAL_CHAR(' ');

    if (code_seen('Z')) {
      float value = code_value_axis_units(Z_AXIS);
      if (Z_PROBE_OFFSET_RANGE_MIN <= value && value <= Z_PROBE_OFFSET_RANGE_MAX) {
        zprobe_zoffset = value;
        SERIAL_ECHO(zprobe_zoffset);
      }
      else {
        SERIAL_ECHOPAIR(MSG_Z_MIN, Z_PROBE_OFFSET_RANGE_MIN);
        SERIAL_CHAR(' ');
        SERIAL_ECHOPAIR(MSG_Z_MAX, Z_PROBE_OFFSET_RANGE_MAX);
      }
    }
    else {
      SERIAL_ECHOPAIR(": ", zprobe_zoffset);
    }

    SERIAL_EOL;
  }

#endif // HAS_BED_PROBE

#if ENABLED(FILAMENT_CHANGE_FEATURE)

  /**
   * M600: Pause for filament change
   *
   *  E[distance] - Retract the filament this far (negative value)
   *  Z[distance] - Move the Z axis by this distance
   *  X[position] - Move to this X position, with Y
   *  Y[position] - Move to this Y position, with X
   *  L[distance] - Retract distance for removal (manual reload)
   *
   *  Default values are used for omitted arguments.
   *
   */
  inline void gcode_M600() {

    if (thermalManager.tooColdToExtrude(active_extruder)) {
      SERIAL_ERROR_START;
      SERIAL_ERRORLNPGM(MSG_TOO_COLD_FOR_M600);
      return;
    }

    // Show initial message and wait for synchronize steppers
    lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_INIT);
    stepper.synchronize();

    float lastpos[NUM_AXIS];

    // Save current position of all axes
    LOOP_XYZE(i)
      lastpos[i] = destination[i] = current_position[i];

    // Define runplan for move axes
    #if IS_KINEMATIC
      #define RUNPLAN(RATE_MM_S) inverse_kinematics(destination); \
                                 planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], destination[E_AXIS], RATE_MM_S, active_extruder);
    #else
      #define RUNPLAN(RATE_MM_S) line_to_destination(RATE_MM_S);
    #endif

    KEEPALIVE_STATE(IN_HANDLER);

    // Initial retract before move to filament change position
    if (code_seen('E')) destination[E_AXIS] += code_value_axis_units(E_AXIS);
    #if defined(FILAMENT_CHANGE_RETRACT_LENGTH) && FILAMENT_CHANGE_RETRACT_LENGTH > 0
      else destination[E_AXIS] -= FILAMENT_CHANGE_RETRACT_LENGTH;
    #endif

    RUNPLAN(FILAMENT_CHANGE_RETRACT_FEEDRATE);

    // Lift Z axis
    float z_lift = code_seen('Z') ? code_value_axis_units(Z_AXIS) :
      #if defined(FILAMENT_CHANGE_Z_ADD) && FILAMENT_CHANGE_Z_ADD > 0
        FILAMENT_CHANGE_Z_ADD
      #else
        0
      #endif
    ;

    if (z_lift > 0) {
      destination[Z_AXIS] += z_lift;
      NOMORE(destination[Z_AXIS], Z_MAX_POS);
      RUNPLAN(FILAMENT_CHANGE_Z_FEEDRATE);
    }

    // Move XY axes to filament exchange position
    if (code_seen('X')) destination[X_AXIS] = code_value_axis_units(X_AXIS);
    #ifdef FILAMENT_CHANGE_X_POS
      else destination[X_AXIS] = FILAMENT_CHANGE_X_POS;
    #endif

    if (code_seen('Y')) destination[Y_AXIS] = code_value_axis_units(Y_AXIS);
    #ifdef FILAMENT_CHANGE_Y_POS
      else destination[Y_AXIS] = FILAMENT_CHANGE_Y_POS;
    #endif

    RUNPLAN(FILAMENT_CHANGE_XY_FEEDRATE);

    stepper.synchronize();
    lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_UNLOAD);

    // Unload filament
    if (code_seen('L')) destination[E_AXIS] += code_value_axis_units(E_AXIS);
    #if defined(FILAMENT_CHANGE_UNLOAD_LENGTH) && FILAMENT_CHANGE_UNLOAD_LENGTH > 0
      else destination[E_AXIS] -= FILAMENT_CHANGE_UNLOAD_LENGTH;
    #endif

    RUNPLAN(FILAMENT_CHANGE_UNLOAD_FEEDRATE);

    // Synchronize steppers and then disable extruders steppers for manual filament changing
    stepper.synchronize();
    disable_e0();
    disable_e1();
    disable_e2();
    disable_e3();
    delay(100);

    #if HAS_BUZZER
      millis_t next_tick = 0;
    #endif

    // Wait for filament insert by user and press button
    lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_INSERT);

    while (!lcd_clicked()) {
      #if HAS_BUZZER
        millis_t ms = millis();
        if (ms >= next_tick) {
          BUZZ(300, 2000);
          next_tick = ms + 2500; // Beep every 2.5s while waiting
        }
      #endif
      idle(true);
    }
    delay(100);
    while (lcd_clicked()) idle(true);
    delay(100);

    // Show load message
    lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_LOAD);

    // Load filament
    if (code_seen('L')) destination[E_AXIS] -= code_value_axis_units(E_AXIS);
    #if defined(FILAMENT_CHANGE_LOAD_LENGTH) && FILAMENT_CHANGE_LOAD_LENGTH > 0
      else destination[E_AXIS] += FILAMENT_CHANGE_LOAD_LENGTH;
    #endif

    RUNPLAN(FILAMENT_CHANGE_LOAD_FEEDRATE);
    stepper.synchronize();

    #if defined(FILAMENT_CHANGE_EXTRUDE_LENGTH) && FILAMENT_CHANGE_EXTRUDE_LENGTH > 0
      do {
        // Extrude filament to get into hotend
        lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_EXTRUDE);
        destination[E_AXIS] += FILAMENT_CHANGE_EXTRUDE_LENGTH;
        RUNPLAN(FILAMENT_CHANGE_EXTRUDE_FEEDRATE);
        stepper.synchronize();
        // Ask user if more filament should be extruded
        KEEPALIVE_STATE(PAUSED_FOR_USER);
        lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_OPTION);
        while (filament_change_menu_response == FILAMENT_CHANGE_RESPONSE_WAIT_FOR) idle(true);
        KEEPALIVE_STATE(IN_HANDLER);
      } while (filament_change_menu_response != FILAMENT_CHANGE_RESPONSE_RESUME_PRINT);
    #endif

    lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_RESUME);

    KEEPALIVE_STATE(IN_HANDLER);

    // Set extruder to saved position
    current_position[E_AXIS] = lastpos[E_AXIS];
    destination[E_AXIS] = lastpos[E_AXIS];
    planner.set_e_position_mm(current_position[E_AXIS]);

    #if IS_KINEMATIC
      // Move XYZ to starting position, then E
      inverse_kinematics(lastpos);
      planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], destination[E_AXIS], FILAMENT_CHANGE_XY_FEEDRATE, active_extruder);
      planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], lastpos[E_AXIS], FILAMENT_CHANGE_XY_FEEDRATE, active_extruder);
    #else
      // Move XY to starting position, then Z, then E
      destination[X_AXIS] = lastpos[X_AXIS];
      destination[Y_AXIS] = lastpos[Y_AXIS];
      RUNPLAN(FILAMENT_CHANGE_XY_FEEDRATE);
      destination[Z_AXIS] = lastpos[Z_AXIS];
      RUNPLAN(FILAMENT_CHANGE_Z_FEEDRATE);
    #endif
    stepper.synchronize();

    #if ENABLED(FILAMENT_RUNOUT_SENSOR)
      filament_ran_out = false;
    #endif

    // Show status screen
    lcd_filament_change_show_message(FILAMENT_CHANGE_MESSAGE_STATUS);
  }

#endif // FILAMENT_CHANGE_FEATURE

#if ENABLED(DUAL_X_CARRIAGE)

  /**
   * M605: Set dual x-carriage movement mode
   *
   *    M605 S0: Full control mode. The slicer has full control over x-carriage movement
   *    M605 S1: Auto-park mode. The inactive head will auto park/unpark without slicer involvement
   *    M605 S2 [Xnnn] [Rmmm]: Duplication mode. The second extruder will duplicate the first with nnn
   *                         units x-offset and an optional differential hotend temperature of
   *                         mmm degrees. E.g., with "M605 S2 X100 R2" the second extruder will duplicate
   *                         the first with a spacing of 100mm in the x direction and 2 degrees hotter.
   *
   *    Note: the X axis should be homed after changing dual x-carriage mode.
   */
  inline void gcode_M605() {
    stepper.synchronize();
    if (code_seen('S')) dual_x_carriage_mode = code_value_byte();
    switch (dual_x_carriage_mode) {
      case DXC_DUPLICATION_MODE:
        if (code_seen('X')) duplicate_extruder_x_offset = max(code_value_axis_units(X_AXIS), X2_MIN_POS - x_home_pos(0));
        if (code_seen('R')) duplicate_extruder_temp_offset = code_value_temp_diff();
        SERIAL_ECHO_START;
        SERIAL_ECHOPGM(MSG_HOTEND_OFFSET);
        SERIAL_CHAR(' ');
        SERIAL_ECHO(hotend_offset[X_AXIS][0]);
        SERIAL_CHAR(',');
        SERIAL_ECHO(hotend_offset[Y_AXIS][0]);
        SERIAL_CHAR(' ');
        SERIAL_ECHO(duplicate_extruder_x_offset);
        SERIAL_CHAR(',');
        SERIAL_ECHOLN(hotend_offset[Y_AXIS][1]);
        break;
      case DXC_FULL_CONTROL_MODE:
      case DXC_AUTO_PARK_MODE:
        break;
      default:
        dual_x_carriage_mode = DEFAULT_DUAL_X_CARRIAGE_MODE;
        break;
    }
    active_extruder_parked = false;
    extruder_duplication_enabled = false;
    delayed_move_time = 0;
  }

#elif ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)

  inline void gcode_M605() {
    stepper.synchronize();
    extruder_duplication_enabled = code_seen('S') && code_value_int() == 2;
    SERIAL_ECHO_START;
    SERIAL_ECHOLNPAIR(MSG_DUPLICATION_MODE, extruder_duplication_enabled ? MSG_ON : MSG_OFF);
  }

#endif // M605

#if ENABLED(LIN_ADVANCE)
  /**
   * M905: Set advance factor
   */
  inline void gcode_M905() {
    stepper.synchronize();
    stepper.advance_M905(code_seen('K') ? code_value_float() : -1.0);
  }
#endif

/**
 * M907: Set digital trimpot motor current using axis codes X, Y, Z, E, B, S
 */
inline void gcode_M907() {
  #if HAS_DIGIPOTSS
    LOOP_XYZE(i)
      if (code_seen(axis_codes[i])) stepper.digipot_current(i, code_value_int());
    if (code_seen('B')) stepper.digipot_current(4, code_value_int());
    if (code_seen('S')) for (int i = 0; i <= 4; i++) stepper.digipot_current(i, code_value_int());
  #endif
  #if PIN_EXISTS(MOTOR_CURRENT_PWM_XY)
    if (code_seen('X')) stepper.digipot_current(0, code_value_int());
  #endif
  #if PIN_EXISTS(MOTOR_CURRENT_PWM_Z)
    if (code_seen('Z')) stepper.digipot_current(1, code_value_int());
  #endif
  #if PIN_EXISTS(MOTOR_CURRENT_PWM_E)
    if (code_seen('E')) stepper.digipot_current(2, code_value_int());
  #endif
  #if ENABLED(DIGIPOT_I2C)
    // this one uses actual amps in floating point
    LOOP_XYZE(i) if (code_seen(axis_codes[i])) digipot_i2c_set_current(i, code_value_float());
    // for each additional extruder (named B,C,D,E..., channels 4,5,6,7...)
    for (int i = NUM_AXIS; i < DIGIPOT_I2C_NUM_CHANNELS; i++) if (code_seen('B' + i - (NUM_AXIS))) digipot_i2c_set_current(i, code_value_float());
  #endif
  #if ENABLED(DAC_STEPPER_CURRENT)
    if (code_seen('S')) {
      float dac_percent = code_value_float();
      for (uint8_t i = 0; i <= 4; i++) dac_current_percent(i, dac_percent);
    }
    LOOP_XYZE(i) if (code_seen(axis_codes[i])) dac_current_percent(i, code_value_float());
  #endif
}

#if HAS_DIGIPOTSS || ENABLED(DAC_STEPPER_CURRENT)

  /**
   * M908: Control digital trimpot directly (M908 P<pin> S<current>)
   */
  inline void gcode_M908() {
    #if HAS_DIGIPOTSS
      stepper.digitalPotWrite(
        code_seen('P') ? code_value_int() : 0,
        code_seen('S') ? code_value_int() : 0
      );
    #endif
    #ifdef DAC_STEPPER_CURRENT
      dac_current_raw(
        code_seen('P') ? code_value_byte() : -1,
        code_seen('S') ? code_value_ushort() : 0
      );
    #endif
  }

  #if ENABLED(DAC_STEPPER_CURRENT) // As with Printrbot RevF

    inline void gcode_M909() { dac_print_values(); }

    inline void gcode_M910() { dac_commit_eeprom(); }

  #endif

#endif // HAS_DIGIPOTSS || DAC_STEPPER_CURRENT

#if HAS_MICROSTEPS

  // M350 Set microstepping mode. Warning: Steps per unit remains unchanged. S code sets stepping mode for all drivers.
  inline void gcode_M350() {
    if (code_seen('S')) for (int i = 0; i <= 4; i++) stepper.microstep_mode(i, code_value_byte());
    LOOP_XYZE(i) if (code_seen(axis_codes[i])) stepper.microstep_mode(i, code_value_byte());
    if (code_seen('B')) stepper.microstep_mode(4, code_value_byte());
    stepper.microstep_readings();
  }

  /**
   * M351: Toggle MS1 MS2 pins directly with axis codes X Y Z E B
   *       S# determines MS1 or MS2, X# sets the pin high/low.
   */
  inline void gcode_M351() {
    if (code_seen('S')) switch (code_value_byte()) {
      case 1:
        LOOP_XYZE(i) if (code_seen(axis_codes[i])) stepper.microstep_ms(i, code_value_byte(), -1);
        if (code_seen('B')) stepper.microstep_ms(4, code_value_byte(), -1);
        break;
      case 2:
        LOOP_XYZE(i) if (code_seen(axis_codes[i])) stepper.microstep_ms(i, -1, code_value_byte());
        if (code_seen('B')) stepper.microstep_ms(4, -1, code_value_byte());
        break;
    }
    stepper.microstep_readings();
  }

#endif // HAS_MICROSTEPS

#if ENABLED(MIXING_EXTRUDER)

  /**
   * M163: Set a single mix factor for a mixing extruder
   *       This is called "weight" by some systems.
   *
   *   S[index]   The channel index to set
   *   P[float]   The mix value
   *
   */
  inline void gcode_M163() {
    int mix_index = code_seen('S') ? code_value_int() : 0;
    float mix_value = code_seen('P') ? code_value_float() : 0.0;
    if (mix_index < MIXING_STEPPERS) mixing_factor[mix_index] = mix_value;
  }

  #if MIXING_VIRTUAL_TOOLS > 1

    /**
     * M164: Store the current mix factors as a virtual tool.
     *
     *   S[index]   The virtual tool to store
     *
     */
    inline void gcode_M164() {
      int tool_index = code_seen('S') ? code_value_int() : 0;
      if (tool_index < MIXING_VIRTUAL_TOOLS) {
        normalize_mix();
        for (uint8_t i = 0; i < MIXING_STEPPERS; i++)
          mixing_virtual_tool_mix[tool_index][i] = mixing_factor[i];
      }
    }

  #endif

  #if ENABLED(DIRECT_MIXING_IN_G1)
    /**
     * M165: Set multiple mix factors for a mixing extruder.
     *       Factors that are left out will be set to 0.
     *       All factors together must add up to 1.0.
     *
     *   A[factor] Mix factor for extruder stepper 1
     *   B[factor] Mix factor for extruder stepper 2
     *   C[factor] Mix factor for extruder stepper 3
     *   D[factor] Mix factor for extruder stepper 4
     *   H[factor] Mix factor for extruder stepper 5
     *   I[factor] Mix factor for extruder stepper 6
     *
     */
    inline void gcode_M165() { gcode_get_mix(); }
  #endif

#endif // MIXING_EXTRUDER

/**
 * M999: Restart after being stopped
 *
 * Default behaviour is to flush the serial buffer and request
 * a resend to the host starting on the last N line received.
 *
 * Sending "M999 S1" will resume printing without flushing the
 * existing command buffer.
 *
 */
inline void gcode_M999() {
  Running = true;
  lcd_reset_alert_level();

  if (code_seen('S') && code_value_bool()) return;

  // gcode_LastN = Stopped_gcode_LastN;
  FlushSerialRequestResend();
}

#if ENABLED(SWITCHING_EXTRUDER)
  inline void move_extruder_servo(uint8_t e) {
    const int angles[2] = SWITCHING_EXTRUDER_SERVO_ANGLES;
    MOVE_SERVO(SWITCHING_EXTRUDER_SERVO_NR, angles[e]);
  }
#endif

inline void invalid_extruder_error(const uint8_t &e) {
  SERIAL_ECHO_START;
  SERIAL_CHAR('T');
  SERIAL_PROTOCOL_F(e, DEC);
  SERIAL_ECHOLN(MSG_INVALID_EXTRUDER);
}

/**
 * Perform a tool-change, which may result in moving the
 * previous tool out of the way and the new tool into place.
 */
void tool_change(const uint8_t tmp_extruder, const float fr_mm_s/*=0.0*/, bool no_move/*=false*/) {
  #if ENABLED(MIXING_EXTRUDER) && MIXING_VIRTUAL_TOOLS > 1

    if (tmp_extruder >= MIXING_VIRTUAL_TOOLS) {
      invalid_extruder_error(tmp_extruder);
      return;
    }

    // T0-Tnnn: Switch virtual tool by changing the mix
    for (uint8_t j = 0; j < MIXING_STEPPERS; j++)
      mixing_factor[j] = mixing_virtual_tool_mix[tmp_extruder][j];

  #else //!MIXING_EXTRUDER || MIXING_VIRTUAL_TOOLS <= 1

    #if HOTENDS > 1

      if (tmp_extruder >= EXTRUDERS) {
        invalid_extruder_error(tmp_extruder);
        return;
      }

      float old_feedrate_mm_s = feedrate_mm_s;

      feedrate_mm_s = fr_mm_s > 0.0 ? (old_feedrate_mm_s = fr_mm_s) : XY_PROBE_FEEDRATE_MM_S;

      if (tmp_extruder != active_extruder) {
        if (!no_move && axis_unhomed_error(true, true, true)) {
          SERIAL_ECHOLNPGM("No move on toolchange");
          no_move = true;
        }

        // Save current position to destination, for use later
        set_destination_to_current();

        #if ENABLED(DUAL_X_CARRIAGE)

          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) {
              SERIAL_ECHOPGM("Dual X Carriage Mode ");
              switch (dual_x_carriage_mode) {
                case DXC_DUPLICATION_MODE: SERIAL_ECHOLNPGM("DXC_DUPLICATION_MODE"); break;
                case DXC_AUTO_PARK_MODE: SERIAL_ECHOLNPGM("DXC_AUTO_PARK_MODE"); break;
                case DXC_FULL_CONTROL_MODE: SERIAL_ECHOLNPGM("DXC_FULL_CONTROL_MODE"); break;
              }
            }
          #endif

          if (dual_x_carriage_mode == DXC_AUTO_PARK_MODE && IsRunning() &&
              (delayed_move_time || current_position[X_AXIS] != x_home_pos(active_extruder))
          ) {
            #if ENABLED(DEBUG_LEVELING_FEATURE)
              if (DEBUGGING(LEVELING)) {
                SERIAL_ECHOPAIR("Raise to ", current_position[Z_AXIS] + TOOLCHANGE_PARK_ZLIFT); SERIAL_EOL;
                SERIAL_ECHOPAIR("MoveX to ", x_home_pos(active_extruder)); SERIAL_EOL;
                SERIAL_ECHOPAIR("Lower to ", current_position[Z_AXIS]); SERIAL_EOL;
              }
            #endif
            // Park old head: 1) raise 2) move to park position 3) lower
            for (uint8_t i = 0; i < 3; i++)
              planner.buffer_line(
                i == 0 ? current_position[X_AXIS] : x_home_pos(active_extruder),
                current_position[Y_AXIS],
                current_position[Z_AXIS] + (i == 2 ? 0 : TOOLCHANGE_PARK_ZLIFT),
                current_position[E_AXIS],
                planner.max_feedrate_mm_s[i == 1 ? X_AXIS : Z_AXIS],
                active_extruder
              );
            stepper.synchronize();
          }

          // apply Y & Z extruder offset (x offset is already used in determining home pos)
          current_position[Y_AXIS] -= hotend_offset[Y_AXIS][active_extruder] - hotend_offset[Y_AXIS][tmp_extruder];
          current_position[Z_AXIS] -= hotend_offset[Z_AXIS][active_extruder] - hotend_offset[Z_AXIS][tmp_extruder];
          active_extruder = tmp_extruder;

          // This function resets the max/min values - the current position may be overwritten below.
          set_axis_is_at_home(X_AXIS);

          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) DEBUG_POS("New Extruder", current_position);
          #endif

          switch (dual_x_carriage_mode) {
            case DXC_FULL_CONTROL_MODE:
              current_position[X_AXIS] = LOGICAL_X_POSITION(inactive_extruder_x_pos);
              inactive_extruder_x_pos = RAW_X_POSITION(destination[X_AXIS]);
              break;
            case DXC_DUPLICATION_MODE:
              active_extruder_parked = (active_extruder == 0); // this triggers the second extruder to move into the duplication position
              if (active_extruder_parked)
                current_position[X_AXIS] = LOGICAL_X_POSITION(inactive_extruder_x_pos);
              else
                current_position[X_AXIS] = destination[X_AXIS] + duplicate_extruder_x_offset;
              inactive_extruder_x_pos = RAW_X_POSITION(destination[X_AXIS]);
              extruder_duplication_enabled = false;
              break;
            default:
              // record raised toolhead position for use by unpark
              memcpy(raised_parked_position, current_position, sizeof(raised_parked_position));
              raised_parked_position[Z_AXIS] += TOOLCHANGE_UNPARK_ZLIFT;
              active_extruder_parked = true;
              delayed_move_time = 0;
              break;
          }

          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) {
              SERIAL_ECHOLNPAIR("Active extruder parked: ", active_extruder_parked ? "yes" : "no");
              DEBUG_POS("New extruder (parked)", current_position);
            }
          #endif

          // No extra case for AUTO_BED_LEVELING_FEATURE in DUAL_X_CARRIAGE. Does that mean they don't work together?
        #else // !DUAL_X_CARRIAGE

          #if ENABLED(SWITCHING_EXTRUDER)
            // <0 if the new nozzle is higher, >0 if lower. A bigger raise when lower.
            float z_diff = hotend_offset[Z_AXIS][active_extruder] - hotend_offset[Z_AXIS][tmp_extruder],
                  z_raise = 0.3 + (z_diff > 0.0 ? z_diff : 0.0);

            // Always raise by some amount
            planner.buffer_line(
              current_position[X_AXIS],
              current_position[Y_AXIS],
              current_position[Z_AXIS] + z_raise,
              current_position[E_AXIS],
              planner.max_feedrate_mm_s[Z_AXIS],
              active_extruder
            );
            stepper.synchronize();

            move_extruder_servo(active_extruder);
            delay(500);

            // Move back down, if needed
            if (z_raise != z_diff) {
              planner.buffer_line(
                current_position[X_AXIS],
                current_position[Y_AXIS],
                current_position[Z_AXIS] + z_diff,
                current_position[E_AXIS],
                planner.max_feedrate_mm_s[Z_AXIS],
                active_extruder
              );
              stepper.synchronize();
            }
          #endif

          /**
           * Set current_position to the position of the new nozzle.
           * Offsets are based on linear distance, so we need to get
           * the resulting position in coordinate space.
           *
           * - With grid or 3-point leveling, offset XYZ by a tilted vector
           * - With mesh leveling, update Z for the new position
           * - Otherwise, just use the raw linear distance
           *
           * Software endstops are altered here too. Consider a case where:
           *   E0 at X=0 ... E1 at X=10
           * When we switch to E1 now X=10, but E1 can't move left.
           * To express this we apply the change in XY to the software endstops.
           * E1 can move farther right than E0, so the right limit is extended.
           *
           * Note that we don't adjust the Z software endstops. Why not?
           * Consider a case where Z=0 (here) and switching to E1 makes Z=1
           * because the bed is 1mm lower at the new position. As long as
           * the first nozzle is out of the way, the carriage should be
           * allowed to move 1mm lower. This technically "breaks" the
           * Z software endstop. But this is technically correct (and
           * there is no viable alternative).
           */
          #if ENABLED(AUTO_BED_LEVELING_LINEAR)
            // Offset extruder, make sure to apply the bed level rotation matrix
            vector_3 tmp_offset_vec = vector_3(hotend_offset[X_AXIS][tmp_extruder],
                                               hotend_offset[Y_AXIS][tmp_extruder],
                                               0),
                     act_offset_vec = vector_3(hotend_offset[X_AXIS][active_extruder],
                                               hotend_offset[Y_AXIS][active_extruder],
                                               0),
                     offset_vec = tmp_offset_vec - act_offset_vec;

            #if ENABLED(DEBUG_LEVELING_FEATURE)
              if (DEBUGGING(LEVELING)) {
                tmp_offset_vec.debug("tmp_offset_vec");
                act_offset_vec.debug("act_offset_vec");
                offset_vec.debug("offset_vec (BEFORE)");
              }
            #endif

            offset_vec.apply_rotation(planner.bed_level_matrix.transpose(planner.bed_level_matrix));

            #if ENABLED(DEBUG_LEVELING_FEATURE)
              if (DEBUGGING(LEVELING)) offset_vec.debug("offset_vec (AFTER)");
            #endif

            // Adjustments to the current position
            float xydiff[2] = { offset_vec.x, offset_vec.y };
            current_position[Z_AXIS] += offset_vec.z;

          #else // !AUTO_BED_LEVELING_LINEAR

            float xydiff[2] = {
              hotend_offset[X_AXIS][tmp_extruder] - hotend_offset[X_AXIS][active_extruder],
              hotend_offset[Y_AXIS][tmp_extruder] - hotend_offset[Y_AXIS][active_extruder]
            };

            #if ENABLED(MESH_BED_LEVELING)

              if (mbl.active()) {
                #if ENABLED(DEBUG_LEVELING_FEATURE)
                  if (DEBUGGING(LEVELING)) SERIAL_ECHOPAIR("Z before MBL: ", current_position[Z_AXIS]);
                #endif
                float xpos = RAW_CURRENT_POSITION(X_AXIS),
                      ypos = RAW_CURRENT_POSITION(Y_AXIS);
                current_position[Z_AXIS] += mbl.get_z(xpos + xydiff[X_AXIS], ypos + xydiff[Y_AXIS]) - mbl.get_z(xpos, ypos);
                #if ENABLED(DEBUG_LEVELING_FEATURE)
                  if (DEBUGGING(LEVELING))
                    SERIAL_ECHOLNPAIR(" after: ", current_position[Z_AXIS]);
                #endif
              }

            #endif // MESH_BED_LEVELING

          #endif // !AUTO_BED_LEVELING_FEATURE

          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) {
              SERIAL_ECHOPAIR("Offset Tool XY by { ", xydiff[X_AXIS]);
              SERIAL_ECHOPAIR(", ", xydiff[Y_AXIS]);
              SERIAL_ECHOLNPGM(" }");
            }
          #endif

          // The newly-selected extruder XY is actually at...
          current_position[X_AXIS] += xydiff[X_AXIS];
          current_position[Y_AXIS] += xydiff[Y_AXIS];
          for (uint8_t i = X_AXIS; i <= Y_AXIS; i++) {
            position_shift[i] += xydiff[i];
            update_software_endstops((AxisEnum)i);
          }

          // Set the new active extruder
          active_extruder = tmp_extruder;

        #endif // !DUAL_X_CARRIAGE

        #if ENABLED(DEBUG_LEVELING_FEATURE)
          if (DEBUGGING(LEVELING)) DEBUG_POS("Sync After Toolchange", current_position);
        #endif

        // Tell the planner the new "current position"
        SYNC_PLAN_POSITION_KINEMATIC();

        // Move to the "old position" (move the extruder into place)
        if (!no_move && IsRunning()) {
          #if ENABLED(DEBUG_LEVELING_FEATURE)
            if (DEBUGGING(LEVELING)) DEBUG_POS("Move back", destination);
          #endif
          prepare_move_to_destination();
        }

      } // (tmp_extruder != active_extruder)

      stepper.synchronize();

      #if ENABLED(EXT_SOLENOID)
        disable_all_solenoids();
        enable_solenoid_on_active_extruder();
      #endif // EXT_SOLENOID

      feedrate_mm_s = old_feedrate_mm_s;

    #else // HOTENDS <= 1

      // Set the new active extruder
      active_extruder = tmp_extruder;

      UNUSED(fr_mm_s);
      UNUSED(no_move);

    #endif // HOTENDS <= 1

    SERIAL_ECHO_START;
    SERIAL_ECHOLNPAIR(MSG_ACTIVE_EXTRUDER, (int)active_extruder);

  #endif //!MIXING_EXTRUDER || MIXING_VIRTUAL_TOOLS <= 1
}

/**
 * T0-T3: Switch tool, usually switching extruders
 *
 *   F[units/min] Set the movement feedrate
 *   S1           Don't move the tool in XY after change
 */
inline void gcode_T(uint8_t tmp_extruder) {

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      SERIAL_ECHOPAIR(">>> gcode_T(", tmp_extruder);
      SERIAL_ECHOLNPGM(")");
      DEBUG_POS("BEFORE", current_position);
    }
  #endif

  #if HOTENDS == 1 || (ENABLED(MIXING_EXTRUDER) && MIXING_VIRTUAL_TOOLS > 1)

    tool_change(tmp_extruder);

  #elif HOTENDS > 1

    tool_change(
      tmp_extruder,
      code_seen('F') ? MMM_TO_MMS(code_value_axis_units(X_AXIS)) : 0.0,
      (tmp_extruder == active_extruder) || (code_seen('S') && code_value_bool())
    );

  #endif

  #if ENABLED(DEBUG_LEVELING_FEATURE)
    if (DEBUGGING(LEVELING)) {
      DEBUG_POS("AFTER", current_position);
      SERIAL_ECHOLNPGM("<<< gcode_T");
    }
  #endif
}

/**
 * Process a single command and dispatch it to its handler
 * This is called from the main loop()
 */
void process_next_command() {
  current_command = command_queue[cmd_queue_index_r];

  if (DEBUGGING(ECHO)) {
    SERIAL_ECHO_START;
    SERIAL_ECHOLN(current_command);
  }

  // Sanitize the current command:
  //  - Skip leading spaces
  //  - Bypass N[-0-9][0-9]*[ ]*
  //  - Overwrite * with nul to mark the end
  while (*current_command == ' ') ++current_command;
  if (*current_command == 'N' && NUMERIC_SIGNED(current_command[1])) {
    current_command += 2; // skip N[-0-9]
    while (NUMERIC(*current_command)) ++current_command; // skip [0-9]*
    while (*current_command == ' ') ++current_command; // skip [ ]*
  }
  char* starpos = strchr(current_command, '*');  // * should always be the last parameter
  if (starpos) while (*starpos == ' ' || *starpos == '*') *starpos-- = '\0'; // nullify '*' and ' '

  char *cmd_ptr = current_command;

  // Get the command code, which must be G, M, or T
  char command_code = *cmd_ptr++;

  // Skip spaces to get the numeric part
  while (*cmd_ptr == ' ') cmd_ptr++;

  uint16_t codenum = 0; // define ahead of goto

  // Bail early if there's no code
  bool code_is_good = NUMERIC(*cmd_ptr);
  if (!code_is_good) goto ExitUnknownCommand;

  // Get and skip the code number
  do {
    codenum = (codenum * 10) + (*cmd_ptr - '0');
    cmd_ptr++;
  } while (NUMERIC(*cmd_ptr));

  // Skip all spaces to get to the first argument, or nul
  while (*cmd_ptr == ' ') cmd_ptr++;

  // The command's arguments (if any) start here, for sure!
  current_command_args = cmd_ptr;

  KEEPALIVE_STATE(IN_HANDLER);

  // Handle a known G, M, or T
  switch (command_code) {
    case 'G': switch (codenum) {

      // G0, G1
      case 0:
      case 1:
        #if IS_SCARA
          gcode_G0_G1(codenum == 0);
        #else
          gcode_G0_G1();
        #endif
        break;

      // G2, G3
      #if ENABLED(ARC_SUPPORT) && DISABLED(SCARA)
        case 2: // G2  - CW ARC
        case 3: // G3  - CCW ARC
          gcode_G2_G3(codenum == 2);
          break;
      #endif

      // G4 Dwell
      case 4:
        gcode_G4();
        break;

      #if ENABLED(BEZIER_CURVE_SUPPORT)
        // G5
        case 5: // G5  - Cubic B_spline
          gcode_G5();
          break;
      #endif // BEZIER_CURVE_SUPPORT

      #if ENABLED(FWRETRACT)
        case 10: // G10: retract
        case 11: // G11: retract_recover
          gcode_G10_G11(codenum == 10);
          break;
      #endif // FWRETRACT

      #if ENABLED(NOZZLE_CLEAN_FEATURE)
        case 12:
          gcode_G12(); // G12: Nozzle Clean
          break;
      #endif // NOZZLE_CLEAN_FEATURE

      #if ENABLED(INCH_MODE_SUPPORT)
        case 20: //G20: Inch Mode
          gcode_G20();
          break;

        case 21: //G21: MM Mode
          gcode_G21();
          break;
      #endif // INCH_MODE_SUPPORT

      #if ENABLED(NOZZLE_PARK_FEATURE)
        case 27: // G27: Nozzle Park
          gcode_G27();
          break;
      #endif // NOZZLE_PARK_FEATURE

      case 28: // G28: Home all axes, one at a time
        gcode_G28();
        break;

      #if ENABLED(AUTO_BED_LEVELING_FEATURE) || ENABLED(MESH_BED_LEVELING)
        case 29: // G29 Detailed Z probe, probes the bed at 3 or more points.
          gcode_G29();
          break;
      #endif // AUTO_BED_LEVELING_FEATURE

      #if HAS_BED_PROBE

        case 30: // G30 Single Z probe
          gcode_G30();
          break;

        #if ENABLED(Z_PROBE_SLED)

            case 31: // G31: dock the sled
              gcode_G31();
              break;

            case 32: // G32: undock the sled
              gcode_G32();
              break;

        #endif // Z_PROBE_SLED
      #endif // HAS_BED_PROBE

      case 90: // G90
        relative_mode = false;
        break;
      case 91: // G91
        relative_mode = true;
        break;

      case 92: // G92
        gcode_G92();
        break;
    }
    break;

    case 'M': switch (codenum) {
      #if ENABLED(ULTIPANEL) || ENABLED(EMERGENCY_PARSER)
        case 0: // M0 - Unconditional stop - Wait for user button press on LCD
        case 1: // M1 - Conditional stop - Wait for user button press on LCD
          gcode_M0_M1();
          break;
      #endif // ULTIPANEL

      case 17:
        gcode_M17();
        break;

      #if ENABLED(SDSUPPORT)
        case 20: // M20 - list SD card
          gcode_M20(); break;
        case 21: // M21 - init SD card
          gcode_M21(); break;
        case 22: //M22 - release SD card
          gcode_M22(); break;
        case 23: //M23 - Select file
          gcode_M23(); break;
        case 24: //M24 - Start SD print
          gcode_M24(); break;
        case 25: //M25 - Pause SD print
          gcode_M25(); break;
        case 26: //M26 - Set SD index
          gcode_M26(); break;
        case 27: //M27 - Get SD status
          gcode_M27(); break;
        case 28: //M28 - Start SD write
          gcode_M28(); break;
        case 29: //M29 - Stop SD write
          gcode_M29(); break;
        case 30: //M30 <filename> Delete File
          gcode_M30(); break;
        case 32: //M32 - Select file and start SD print
          gcode_M32(); break;

        #if ENABLED(LONG_FILENAME_HOST_SUPPORT)
          case 33: //M33 - Get the long full path to a file or folder
            gcode_M33(); break;
        #endif // LONG_FILENAME_HOST_SUPPORT

        case 928: //M928 - Start SD write
          gcode_M928(); break;
      #endif //SDSUPPORT

      case 31: //M31 take time since the start of the SD print or an M109 command
        gcode_M31();
        break;

      case 42: //M42 -Change pin status via gcode
        gcode_M42();
        break;

      #if ENABLED(Z_MIN_PROBE_REPEATABILITY_TEST)
        case 48: // M48 Z probe repeatability
          gcode_M48();
          break;
      #endif // Z_MIN_PROBE_REPEATABILITY_TEST

      case 75: // Start print timer
        gcode_M75();
        break;

      case 76: // Pause print timer
        gcode_M76();
        break;

      case 77: // Stop print timer
        gcode_M77();
        break;

      #if ENABLED(PRINTCOUNTER)
        case 78: // Show print statistics
          gcode_M78();
          break;
      #endif

      #if ENABLED(M100_FREE_MEMORY_WATCHER)
        case 100:
          gcode_M100();
          break;
      #endif

      case 104: // M104
        gcode_M104();
        break;

      case 110: // M110: Set Current Line Number
        gcode_M110();
        break;

      case 111: // M111: Set debug level
        gcode_M111();
        break;

      #if DISABLED(EMERGENCY_PARSER)

        case 108: // M108: Cancel Waiting
          gcode_M108();
          break;

        case 112: // M112: Emergency Stop
          gcode_M112();
          break;

        case 410: // M410 quickstop - Abort all the planned moves.
          gcode_M410();
          break;

      #endif

      #if ENABLED(HOST_KEEPALIVE_FEATURE)
        case 113: // M113: Set Host Keepalive interval
          gcode_M113();
          break;
      #endif

      case 140: // M140: Set bed temp
        gcode_M140();
        break;

      case 105: // M105: Read current temperature
        gcode_M105();
        KEEPALIVE_STATE(NOT_BUSY);
        return; // "ok" already printed

      case 109: // M109: Wait for temperature
        gcode_M109();
        break;

      #if HAS_TEMP_BED
        case 190: // M190: Wait for bed heater to reach target
          gcode_M190();
          break;
      #endif // HAS_TEMP_BED

      #if FAN_COUNT > 0
        case 106: // M106: Fan On
          gcode_M106();
          break;
        case 107: // M107: Fan Off
          gcode_M107();
          break;
      #endif // FAN_COUNT > 0

      #if ENABLED(BARICUDA)
        // PWM for HEATER_1_PIN
        #if HAS_HEATER_1
          case 126: // M126: valve open
            gcode_M126();
            break;
          case 127: // M127: valve closed
            gcode_M127();
            break;
        #endif // HAS_HEATER_1

        // PWM for HEATER_2_PIN
        #if HAS_HEATER_2
          case 128: // M128: valve open
            gcode_M128();
            break;
          case 129: // M129: valve closed
            gcode_M129();
            break;
        #endif // HAS_HEATER_2
      #endif // BARICUDA

      #if HAS_POWER_SWITCH

        case 80: // M80: Turn on Power Supply
          gcode_M80();
          break;

      #endif // HAS_POWER_SWITCH

      case 81: // M81: Turn off Power, including Power Supply, if possible
        gcode_M81();
        break;

      case 82:
        gcode_M82();
        break;
      case 83:
        gcode_M83();
        break;
      case 18: // (for compatibility)
      case 84: // M84
        gcode_M18_M84();
        break;
      case 85: // M85
        gcode_M85();
        break;
      case 92: // M92: Set the steps-per-unit for one or more axes
        gcode_M92();
        break;
      case 115: // M115: Report capabilities
        gcode_M115();
        break;
      case 117: // M117: Set LCD message text, if possible
        gcode_M117();
        break;
      case 114: // M114: Report current position
        gcode_M114();
        break;
      case 120: // M120: Enable endstops
        gcode_M120();
        break;
      case 121: // M121: Disable endstops
        gcode_M121();
        break;
      case 119: // M119: Report endstop states
        gcode_M119();
        break;

      #if ENABLED(ULTIPANEL)

        case 145: // M145: Set material heatup parameters
          gcode_M145();
          break;

      #endif

      #if ENABLED(TEMPERATURE_UNITS_SUPPORT)
        case 149:
          gcode_M149();
          break;
      #endif

      #if ENABLED(BLINKM)

        case 150: // M150
          gcode_M150();
          break;

      #endif //BLINKM

      #if ENABLED(EXPERIMENTAL_I2CBUS)

        case 155:
          gcode_M155();
          break;

        case 156:
          gcode_M156();
          break;

      #endif //EXPERIMENTAL_I2CBUS

      #if ENABLED(MIXING_EXTRUDER)
        case 163: // M163 S<int> P<float> set weight for a mixing extruder
          gcode_M163();
          break;
        #if MIXING_VIRTUAL_TOOLS > 1
          case 164: // M164 S<int> save current mix as a virtual extruder
            gcode_M164();
            break;
        #endif
        #if ENABLED(DIRECT_MIXING_IN_G1)
          case 165: // M165 [ABCDHI]<float> set multiple mix weights
            gcode_M165();
            break;
        #endif
      #endif

      case 200: // M200 D<diameter> Set filament diameter and set E axis units to cubic. (Use S0 to revert to linear units.)
        gcode_M200();
        break;
      case 201: // M201
        gcode_M201();
        break;
      #if 0 // Not used for Sprinter/grbl gen6
        case 202: // M202
          gcode_M202();
          break;
      #endif
      case 203: // M203 max feedrate units/sec
        gcode_M203();
        break;
      case 204: // M204 acclereration S normal moves T filmanent only moves
        gcode_M204();
        break;
      case 205: //M205 advanced settings:  minimum travel speed S=while printing T=travel only,  B=minimum segment time X= maximum xy jerk, Z=maximum Z jerk
        gcode_M205();
        break;
      case 206: // M206 additional homing offset
        gcode_M206();
        break;

      #if ENABLED(DELTA)
        case 665: // M665 set delta configurations L<diagonal_rod> R<delta_radius> S<segments_per_sec>
          gcode_M665();
          break;
      #endif

      #if ENABLED(DELTA) || ENABLED(Z_DUAL_ENDSTOPS)
        case 666: // M666 set delta / dual endstop adjustment
          gcode_M666();
          break;
      #endif

      #if ENABLED(FWRETRACT)
        case 207: // M207 - Set Retract Length: S<length>, Feedrate: F<units/min>, and Z lift: Z<distance>
          gcode_M207();
          break;
        case 208: // M208 - Set Recover (unretract) Additional (!) Length: S<length> and Feedrate: F<units/min>
          gcode_M208();
          break;
        case 209: // M209 - Turn Automatic Retract Detection on/off: S<bool> (For slicers that don't support G10/11). Every normal extrude-only move will be classified as retract depending on the direction.
          gcode_M209();
          break;
      #endif // FWRETRACT

      case 211: // M211 - Enable, Disable, and/or Report software endstops
        gcode_M211();
        break;

      #if HOTENDS > 1
        case 218: // M218 - Set a tool offset: T<index> X<offset> Y<offset>
          gcode_M218();
          break;
      #endif

      case 220: // M220 - Set Feedrate Percentage: S<percent> ("FR" on your LCD)
        gcode_M220();
        break;

      case 221: // M221 - Set Flow Percentage: S<percent>
        gcode_M221();
        break;

      case 226: // M226 P<pin number> S<pin state>- Wait until the specified pin reaches the state required
        gcode_M226();
        break;

      #if HAS_SERVOS
        case 280: // M280 - set servo position absolute. P: servo index, S: angle or microseconds
          gcode_M280();
          break;
      #endif // HAS_SERVOS

      #if HAS_BUZZER
        case 300: // M300 - Play beep tone
          gcode_M300();
          break;
      #endif // HAS_BUZZER

      #if ENABLED(PIDTEMP)
        case 301: // M301
          gcode_M301();
          break;
      #endif // PIDTEMP

      #if ENABLED(PIDTEMPBED)
        case 304: // M304
          gcode_M304();
          break;
      #endif // PIDTEMPBED

      #if defined(CHDK) || HAS_PHOTOGRAPH
        case 240: // M240  Triggers a camera by emulating a Canon RC-1 : http://www.doc-diy.net/photo/rc-1_hacked/
          gcode_M240();
          break;
      #endif // CHDK || PHOTOGRAPH_PIN

      #if HAS_LCD_CONTRAST
        case 250: // M250  Set LCD contrast value: C<value> (value 0..63)
          gcode_M250();
          break;
      #endif // HAS_LCD_CONTRAST

      #if ENABLED(PREVENT_COLD_EXTRUSION)
        case 302: // allow cold extrudes, or set the minimum extrude temperature
          gcode_M302();
          break;
      #endif // PREVENT_COLD_EXTRUSION

      case 303: // M303 PID autotune
        gcode_M303();
        break;

      #if ENABLED(MORGAN_SCARA)
        case 360:  // M360 SCARA Theta pos1
          if (gcode_M360()) return;
          break;
        case 361:  // M361 SCARA Theta pos2
          if (gcode_M361()) return;
          break;
        case 362:  // M362 SCARA Psi pos1
          if (gcode_M362()) return;
          break;
        case 363:  // M363 SCARA Psi pos2
          if (gcode_M363()) return;
          break;
        case 364:  // M364 SCARA Psi pos3 (90 deg to Theta)
          if (gcode_M364()) return;
          break;
      #endif // SCARA

      case 400: // M400 finish all moves
        gcode_M400();
        break;

      #if HAS_BED_PROBE
        case 401:
          gcode_M401();
          break;
        case 402:
          gcode_M402();
          break;
      #endif // HAS_BED_PROBE

      #if ENABLED(FILAMENT_WIDTH_SENSOR)
        case 404:  //M404 Enter the nominal filament width (3mm, 1.75mm ) N<3.0> or display nominal filament width
          gcode_M404();
          break;
        case 405:  //M405 Turn on filament sensor for control
          gcode_M405();
          break;
        case 406:  //M406 Turn off filament sensor for control
          gcode_M406();
          break;
        case 407:   //M407 Display measured filament diameter
          gcode_M407();
          break;
      #endif // ENABLED(FILAMENT_WIDTH_SENSOR)

      #if ENABLED(MESH_BED_LEVELING)
        case 420: // M420 Enable/Disable Mesh Bed Leveling
          gcode_M420();
          break;
        case 421: // M421 Set a Mesh Bed Leveling Z coordinate
          gcode_M421();
          break;
      #endif

      case 428: // M428 Apply current_position to home_offset
        gcode_M428();
        break;

      case 500: // M500 Store settings in EEPROM
        gcode_M500();
        break;
      case 501: // M501 Read settings from EEPROM
        gcode_M501();
        break;
      case 502: // M502 Revert to default settings
        gcode_M502();
        break;
      case 503: // M503 print settings currently in memory
        gcode_M503();
        break;

      #if ENABLED(ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
        case 540:
          gcode_M540();
          break;
      #endif

      #if HAS_BED_PROBE
        case 851: // Set Z Probe Z Offset
          gcode_M851();
          break;
      #endif // HAS_BED_PROBE

      #if ENABLED(FILAMENT_CHANGE_FEATURE)
        case 600: //Pause for filament change X[pos] Y[pos] Z[relative lift] E[initial retract] L[later retract distance for removal]
          gcode_M600();
          break;
      #endif // FILAMENT_CHANGE_FEATURE

      #if ENABLED(DUAL_X_CARRIAGE)
        case 605:
          gcode_M605();
          break;
      #endif // DUAL_X_CARRIAGE

      #if ENABLED(LIN_ADVANCE)
        case 905: // M905 Set advance factor.
          gcode_M905();
          break;
      #endif

      case 907: // M907 Set digital trimpot motor current using axis codes.
        gcode_M907();
        break;

      #if HAS_DIGIPOTSS || ENABLED(DAC_STEPPER_CURRENT)

        case 908: // M908 Control digital trimpot directly.
          gcode_M908();
          break;

        #if ENABLED(DAC_STEPPER_CURRENT) // As with Printrbot RevF

          case 909: // M909 Print digipot/DAC current value
            gcode_M909();
            break;

          case 910: // M910 Commit digipot/DAC value to external EEPROM
            gcode_M910();
            break;

        #endif

      #endif // HAS_DIGIPOTSS || DAC_STEPPER_CURRENT

      #if HAS_MICROSTEPS

        case 350: // M350 Set microstepping mode. Warning: Steps per unit remains unchanged. S code sets stepping mode for all drivers.
          gcode_M350();
          break;

        case 351: // M351 Toggle MS1 MS2 pins directly, S# determines MS1 or MS2, X# sets the pin high/low.
          gcode_M351();
          break;

      #endif // HAS_MICROSTEPS

      case 999: // M999: Restart after being Stopped
        gcode_M999();
        break;
    }
    break;

    case 'T':
      gcode_T(codenum);
      break;

    default: code_is_good = false;
  }

  KEEPALIVE_STATE(NOT_BUSY);

ExitUnknownCommand:

  // Still unknown command? Throw an error
  if (!code_is_good) unknown_command_error();

  ok_to_send();
}

/**
 * Send a "Resend: nnn" message to the host to
 * indicate that a command needs to be re-sent.
 */
void FlushSerialRequestResend() {
  //char command_queue[cmd_queue_index_r][100]="Resend:";
  MYSERIAL.flush();
  SERIAL_PROTOCOLPGM(MSG_RESEND);
  SERIAL_PROTOCOLLN(gcode_LastN + 1);
  ok_to_send();
}

/**
 * Send an "ok" message to the host, indicating
 * that a command was successfully processed.
 *
 * If ADVANCED_OK is enabled also include:
 *   N<int>  Line number of the command, if any
 *   P<int>  Planner space remaining
 *   B<int>  Block queue space remaining
 */
void ok_to_send() {
  refresh_cmd_timeout();
  if (!send_ok[cmd_queue_index_r]) return;
  SERIAL_PROTOCOLPGM(MSG_OK);
  #if ENABLED(ADVANCED_OK)
    char* p = command_queue[cmd_queue_index_r];
    if (*p == 'N') {
      SERIAL_PROTOCOL(' ');
      SERIAL_ECHO(*p++);
      while (NUMERIC_SIGNED(*p))
        SERIAL_ECHO(*p++);
    }
    SERIAL_PROTOCOLPGM(" P"); SERIAL_PROTOCOL(int(BLOCK_BUFFER_SIZE - planner.movesplanned() - 1));
    SERIAL_PROTOCOLPGM(" B"); SERIAL_PROTOCOL(BUFSIZE - commands_in_queue);
  #endif
  SERIAL_EOL;
}

#if ENABLED(min_software_endstops) || ENABLED(max_software_endstops)

  /**
   * Constrain the given coordinates to the software endstops.
   */
  void clamp_to_software_endstops(float target[XYZ]) {
    #if ENABLED(min_software_endstops)
      NOLESS(target[X_AXIS], soft_endstop_min[X_AXIS]);
      NOLESS(target[Y_AXIS], soft_endstop_min[Y_AXIS]);
      NOLESS(target[Z_AXIS], soft_endstop_min[Z_AXIS]);
    #endif
    #if ENABLED(max_software_endstops)
      NOMORE(target[X_AXIS], soft_endstop_max[X_AXIS]);
      NOMORE(target[Y_AXIS], soft_endstop_max[Y_AXIS]);
      NOMORE(target[Z_AXIS], soft_endstop_max[Z_AXIS]);
    #endif
  }

#endif

#if ENABLED(AUTO_BED_LEVELING_NONLINEAR)

  // Get the Z adjustment for non-linear bed leveling
  float nonlinear_z_offset(float cartesian[XYZ]) {

    int half_x = (ABL_GRID_POINTS_X - 1) / 2,
        half_y = (ABL_GRID_POINTS_Y - 1) / 2;
    float hx2 = half_x - 0.001, hx1 = -hx2,
          hy2 = half_y - 0.001, hy1 = -hy2,
          grid_x = max(hx1, min(hx2, RAW_X_POSITION(cartesian[X_AXIS]) / nonlinear_grid_spacing[X_AXIS])),
          grid_y = max(hy1, min(hy2, RAW_Y_POSITION(cartesian[Y_AXIS]) / nonlinear_grid_spacing[Y_AXIS]));
    int   floor_x = floor(grid_x), floor_y = floor(grid_y);
    float ratio_x = grid_x - floor_x, ratio_y = grid_y - floor_y,
          z1 = bed_level_grid[floor_x + half_x][floor_y + half_y],
          z2 = bed_level_grid[floor_x + half_x][floor_y + half_y + 1],
          z3 = bed_level_grid[floor_x + half_x + 1][floor_y + half_y],
          z4 = bed_level_grid[floor_x + half_x + 1][floor_y + half_y + 1],
          left = (1 - ratio_y) * z1 + ratio_y * z2,
          right = (1 - ratio_y) * z3 + ratio_y * z4;

    /*
      SERIAL_ECHOPAIR("grid_x=", grid_x);
      SERIAL_ECHOPAIR(" grid_y=", grid_y);
      SERIAL_ECHOPAIR(" floor_x=", floor_x);
      SERIAL_ECHOPAIR(" floor_y=", floor_y);
      SERIAL_ECHOPAIR(" ratio_x=", ratio_x);
      SERIAL_ECHOPAIR(" ratio_y=", ratio_y);
      SERIAL_ECHOPAIR(" z1=", z1);
      SERIAL_ECHOPAIR(" z2=", z2);
      SERIAL_ECHOPAIR(" z3=", z3);
      SERIAL_ECHOPAIR(" z4=", z4);
      SERIAL_ECHOPAIR(" left=", left);
      SERIAL_ECHOPAIR(" right=", right);
      SERIAL_ECHOPAIR(" offset=", (1 - ratio_x) * left + ratio_x * right);
    //*/

    return (1 - ratio_x) * left + ratio_x * right;
  }

#endif // AUTO_BED_LEVELING_NONLINEAR

#if ENABLED(DELTA)

  /**
   * Recalculate factors used for delta kinematics whenever
   * settings have been changed (e.g., by M665).
   */
  void recalc_delta_settings(float radius, float diagonal_rod) {
    delta_tower1_x = -SIN_60 * (radius + DELTA_RADIUS_TRIM_TOWER_1);  // front left tower
    delta_tower1_y = -COS_60 * (radius + DELTA_RADIUS_TRIM_TOWER_1);
    delta_tower2_x =  SIN_60 * (radius + DELTA_RADIUS_TRIM_TOWER_2);  // front right tower
    delta_tower2_y = -COS_60 * (radius + DELTA_RADIUS_TRIM_TOWER_2);
    delta_tower3_x = 0.0;                                             // back middle tower
    delta_tower3_y = (radius + DELTA_RADIUS_TRIM_TOWER_3);
    delta_diagonal_rod_2_tower_1 = sq(diagonal_rod + delta_diagonal_rod_trim_tower_1);
    delta_diagonal_rod_2_tower_2 = sq(diagonal_rod + delta_diagonal_rod_trim_tower_2);
    delta_diagonal_rod_2_tower_3 = sq(diagonal_rod + delta_diagonal_rod_trim_tower_3);
  }

  #if ENABLED(DELTA_FAST_SQRT)
    /**
     * Fast inverse sqrt from Quake III Arena
     * See: https://en.wikipedia.org/wiki/Fast_inverse_square_root
     */
    float Q_rsqrt(float number) {
      long i;
      float x2, y;
      const float threehalfs = 1.5f;
      x2 = number * 0.5f;
      y  = number;
      i  = * ( long * ) &y;                       // evil floating point bit level hacking
      i  = 0x5f3759df - ( i >> 1 );               // what the f***?
      y  = * ( float * ) &i;
      y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration
      // y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed
      return y;
    }

    #define _SQRT(n) (1.0f / Q_rsqrt(n))

  #else

    #define _SQRT(n) sqrt(n)

  #endif

  /**
   * Delta Inverse Kinematics
   *
   * Calculate the tower positions for a given logical
   * position, storing the result in the delta[] array.
   *
   * This is an expensive calculation, requiring 3 square
   * roots per segmented linear move, and strains the limits
   * of a Mega2560 with a Graphical Display.
   *
   * Suggested optimizations include:
   *
   * - Disable the home_offset (M206) and/or position_shift (G92)
   *   features to remove up to 12 float additions.
   *
   * - Use a fast-inverse-sqrt function and add the reciprocal.
   *   (see above)
   */

  // Macro to obtain the Z position of an individual tower
  #define DELTA_Z(T) raw[Z_AXIS] + _SQRT(    \
    delta_diagonal_rod_2_tower_##T - HYPOT2( \
        delta_tower##T##_x - raw[X_AXIS],    \
        delta_tower##T##_y - raw[Y_AXIS]     \
      )                                      \
    )

  #define DELTA_RAW_IK() do {   \
    delta[A_AXIS] = DELTA_Z(1); \
    delta[B_AXIS] = DELTA_Z(2); \
    delta[C_AXIS] = DELTA_Z(3); \
  } while(0)

  #define DELTA_LOGICAL_IK() do {      \
    const float raw[XYZ] = {           \
      RAW_X_POSITION(logical[X_AXIS]), \
      RAW_Y_POSITION(logical[Y_AXIS]), \
      RAW_Z_POSITION(logical[Z_AXIS])  \
    };                                 \
    DELTA_RAW_IK();                    \
  } while(0)

  #define DELTA_DEBUG() do { \
      SERIAL_ECHOPAIR("cartesian X:", raw[X_AXIS]); \
      SERIAL_ECHOPAIR(" Y:", raw[Y_AXIS]);          \
      SERIAL_ECHOLNPAIR(" Z:", raw[Z_AXIS]);        \
      SERIAL_ECHOPAIR("delta A:", delta[A_AXIS]);   \
      SERIAL_ECHOPAIR(" B:", delta[B_AXIS]);        \
      SERIAL_ECHOLNPAIR(" C:", delta[C_AXIS]);      \
    } while(0)

  void inverse_kinematics(const float logical[XYZ]) {
    DELTA_LOGICAL_IK();
    // DELTA_DEBUG();
  }

  /**
   * Calculate the highest Z position where the
   * effector has the full range of XY motion.
   */
  float delta_safe_distance_from_top() {
    float cartesian[XYZ] = {
      LOGICAL_X_POSITION(0),
      LOGICAL_Y_POSITION(0),
      LOGICAL_Z_POSITION(0)
    };
    inverse_kinematics(cartesian);
    float distance = delta[A_AXIS];
    cartesian[Y_AXIS] = LOGICAL_Y_POSITION(DELTA_PRINTABLE_RADIUS);
    inverse_kinematics(cartesian);
    return abs(distance - delta[A_AXIS]);
  }

  /**
   * Delta Forward Kinematics
   *
   * See the Wikipedia article "Trilateration"
   * https://en.wikipedia.org/wiki/Trilateration
   *
   * Establish a new coordinate system in the plane of the
   * three carriage points. This system has its origin at
   * tower1, with tower2 on the X axis. Tower3 is in the X-Y
   * plane with a Z component of zero.
   * We will define unit vectors in this coordinate system
   * in our original coordinate system. Then when we calculate
   * the Xnew, Ynew and Znew values, we can translate back into
   * the original system by moving along those unit vectors
   * by the corresponding values.
   *
   * Variable names matched to Marlin, c-version, and avoid the
   * use of any vector library.
   *
   * by Andreas Hardtung 2016-06-07
   * based on a Java function from "Delta Robot Kinematics V3"
   * by Steve Graves
   *
   * The result is stored in the cartes[] array.
   */
  void forward_kinematics_DELTA(float z1, float z2, float z3) {
    // Create a vector in old coordinates along x axis of new coordinate
    float p12[3] = { delta_tower2_x - delta_tower1_x, delta_tower2_y - delta_tower1_y, z2 - z1 };

    // Get the Magnitude of vector.
    float d = sqrt( sq(p12[0]) + sq(p12[1]) + sq(p12[2]) );

    // Create unit vector by dividing by magnitude.
    float ex[3] = { p12[0] / d, p12[1] / d, p12[2] / d };

    // Get the vector from the origin of the new system to the third point.
    float p13[3] = { delta_tower3_x - delta_tower1_x, delta_tower3_y - delta_tower1_y, z3 - z1 };

    // Use the dot product to find the component of this vector on the X axis.
    float i = ex[0] * p13[0] + ex[1] * p13[1] + ex[2] * p13[2];

    // Create a vector along the x axis that represents the x component of p13.
    float iex[3] = { ex[0] * i, ex[1] * i, ex[2] * i };

    // Subtract the X component from the original vector leaving only Y. We use the
    // variable that will be the unit vector after we scale it.
    float ey[3] = { p13[0] - iex[0], p13[1] - iex[1], p13[2] - iex[2] };

    // The magnitude of Y component
    float j = sqrt( sq(ey[0]) + sq(ey[1]) + sq(ey[2]) );

    // Convert to a unit vector
    ey[0] /= j; ey[1] /= j;  ey[2] /= j;

    // The cross product of the unit x and y is the unit z
    // float[] ez = vectorCrossProd(ex, ey);
    float ez[3] = {
      ex[1] * ey[2] - ex[2] * ey[1],
      ex[2] * ey[0] - ex[0] * ey[2],
      ex[0] * ey[1] - ex[1] * ey[0]
    };

    // We now have the d, i and j values defined in Wikipedia.
    // Plug them into the equations defined in Wikipedia for Xnew, Ynew and Znew
    float Xnew = (delta_diagonal_rod_2_tower_1 - delta_diagonal_rod_2_tower_2 + sq(d)) / (d * 2),
          Ynew = ((delta_diagonal_rod_2_tower_1 - delta_diagonal_rod_2_tower_3 + HYPOT2(i, j)) / 2 - i * Xnew) / j,
          Znew = sqrt(delta_diagonal_rod_2_tower_1 - HYPOT2(Xnew, Ynew));

    // Start from the origin of the old coordinates and add vectors in the
    // old coords that represent the Xnew, Ynew and Znew to find the point
    // in the old system.
    cartes[X_AXIS] = delta_tower1_x + ex[0] * Xnew + ey[0] * Ynew - ez[0] * Znew;
    cartes[Y_AXIS] = delta_tower1_y + ex[1] * Xnew + ey[1] * Ynew - ez[1] * Znew;
    cartes[Z_AXIS] =             z1 + ex[2] * Xnew + ey[2] * Ynew - ez[2] * Znew;
  };

  void forward_kinematics_DELTA(float point[ABC]) {
    forward_kinematics_DELTA(point[A_AXIS], point[B_AXIS], point[C_AXIS]);
  }

#endif // DELTA

/**
 * Get the stepper positions in the cartes[] array.
 * Forward kinematics are applied for DELTA and SCARA.
 *
 * The result is in the current coordinate space with
 * leveling applied. The coordinates need to be run through
 * unapply_leveling to obtain the "ideal" coordinates
 * suitable for current_position, etc.
 */
void get_cartesian_from_steppers() {
  #if ENABLED(DELTA)
    forward_kinematics_DELTA(
      stepper.get_axis_position_mm(A_AXIS),
      stepper.get_axis_position_mm(B_AXIS),
      stepper.get_axis_position_mm(C_AXIS)
    );
    cartes[X_AXIS] += LOGICAL_X_POSITION(0);
    cartes[Y_AXIS] += LOGICAL_Y_POSITION(0);
    cartes[Z_AXIS] += LOGICAL_Z_POSITION(0);
  #elif IS_SCARA
    forward_kinematics_SCARA(
      stepper.get_axis_position_degrees(A_AXIS),
      stepper.get_axis_position_degrees(B_AXIS)
    );
    cartes[X_AXIS] += LOGICAL_X_POSITION(0);
    cartes[Y_AXIS] += LOGICAL_Y_POSITION(0);
    cartes[Z_AXIS] = stepper.get_axis_position_mm(Z_AXIS);
  #else
    cartes[X_AXIS] = stepper.get_axis_position_mm(X_AXIS);
    cartes[Y_AXIS] = stepper.get_axis_position_mm(Y_AXIS);
    cartes[Z_AXIS] = stepper.get_axis_position_mm(Z_AXIS);
  #endif
}

/**
 * Set the current_position for an axis based on
 * the stepper positions, removing any leveling that
 * may have been applied.
 */
void set_current_from_steppers_for_axis(const AxisEnum axis) {
  get_cartesian_from_steppers();
  #if PLANNER_LEVELING
    planner.unapply_leveling(cartes);
  #endif
  if (axis == ALL_AXES)
    memcpy(current_position, cartes, sizeof(cartes));
  else
    current_position[axis] = cartes[axis];
}

#if ENABLED(MESH_BED_LEVELING)

  /**
   * Prepare a mesh-leveled linear move in a Cartesian setup,
   * splitting the move where it crosses mesh borders.
   */
  void mesh_line_to_destination(float fr_mm_s, uint8_t x_splits = 0xff, uint8_t y_splits = 0xff) {
    int cx1 = mbl.cell_index_x(RAW_CURRENT_POSITION(X_AXIS)),
        cy1 = mbl.cell_index_y(RAW_CURRENT_POSITION(Y_AXIS)),
        cx2 = mbl.cell_index_x(RAW_X_POSITION(destination[X_AXIS])),
        cy2 = mbl.cell_index_y(RAW_Y_POSITION(destination[Y_AXIS]));
    NOMORE(cx1, MESH_NUM_X_POINTS - 2);
    NOMORE(cy1, MESH_NUM_Y_POINTS - 2);
    NOMORE(cx2, MESH_NUM_X_POINTS - 2);
    NOMORE(cy2, MESH_NUM_Y_POINTS - 2);

    if (cx1 == cx2 && cy1 == cy2) {
      // Start and end on same mesh square
      line_to_destination(fr_mm_s);
      set_current_to_destination();
      return;
    }

    #define MBL_SEGMENT_END(A) (current_position[A ##_AXIS] + (destination[A ##_AXIS] - current_position[A ##_AXIS]) * normalized_dist)

    float normalized_dist, end[NUM_AXIS];

    // Split at the left/front border of the right/top square
    int8_t gcx = max(cx1, cx2), gcy = max(cy1, cy2);
    if (cx2 != cx1 && TEST(x_splits, gcx)) {
      memcpy(end, destination, sizeof(end));
      destination[X_AXIS] = LOGICAL_X_POSITION(mbl.get_probe_x(gcx));
      normalized_dist = (destination[X_AXIS] - current_position[X_AXIS]) / (end[X_AXIS] - current_position[X_AXIS]);
      destination[Y_AXIS] = MBL_SEGMENT_END(Y);
      CBI(x_splits, gcx);
    }
    else if (cy2 != cy1 && TEST(y_splits, gcy)) {
      memcpy(end, destination, sizeof(end));
      destination[Y_AXIS] = LOGICAL_Y_POSITION(mbl.get_probe_y(gcy));
      normalized_dist = (destination[Y_AXIS] - current_position[Y_AXIS]) / (end[Y_AXIS] - current_position[Y_AXIS]);
      destination[X_AXIS] = MBL_SEGMENT_END(X);
      CBI(y_splits, gcy);
    }
    else {
      // Already split on a border
      line_to_destination(fr_mm_s);
      set_current_to_destination();
      return;
    }

    destination[Z_AXIS] = MBL_SEGMENT_END(Z);
    destination[E_AXIS] = MBL_SEGMENT_END(E);

    // Do the split and look for more borders
    mesh_line_to_destination(fr_mm_s, x_splits, y_splits);

    // Restore destination from stack
    memcpy(destination, end, sizeof(end));
    mesh_line_to_destination(fr_mm_s, x_splits, y_splits);
  }

#endif // MESH_BED_LEVELING

#if IS_KINEMATIC

  /**
   * Prepare a linear move in a DELTA or SCARA setup.
   *
   * This calls planner.buffer_line several times, adding
   * small incremental moves for DELTA or SCARA.
   */
  inline bool prepare_kinematic_move_to(float ltarget[NUM_AXIS]) {

    // Get the top feedrate of the move in the XY plane
    float _feedrate_mm_s = MMS_SCALED(feedrate_mm_s);

    // If the move is only in Z/E don't split up the move
    if (ltarget[X_AXIS] == current_position[X_AXIS] && ltarget[Y_AXIS] == current_position[Y_AXIS]) {
      inverse_kinematics(ltarget);
      planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], ltarget[E_AXIS], _feedrate_mm_s, active_extruder);
      return true;
    }

    // Get the cartesian distances moved in XYZE
    float difference[NUM_AXIS];
    LOOP_XYZE(i) difference[i] = ltarget[i] - current_position[i];

    // Get the linear distance in XYZ
    float cartesian_mm = sqrt(sq(difference[X_AXIS]) + sq(difference[Y_AXIS]) + sq(difference[Z_AXIS]));

    // If the move is very short, check the E move distance
    if (UNEAR_ZERO(cartesian_mm)) cartesian_mm = abs(difference[E_AXIS]);

    // No E move either? Game over.
    if (UNEAR_ZERO(cartesian_mm)) return false;

    // Minimum number of seconds to move the given distance
    float seconds = cartesian_mm / _feedrate_mm_s;

    // The number of segments-per-second times the duration
    // gives the number of segments
    uint16_t segments = delta_segments_per_second * seconds;

    // For SCARA minimum segment size is 0.5mm
    #if IS_SCARA
      NOMORE(segments, cartesian_mm * 2);
    #endif

    // At least one segment is required
    NOLESS(segments, 1);

    // The approximate length of each segment
    float segment_distance[XYZE] = {
            difference[X_AXIS] / segments,
            difference[Y_AXIS] / segments,
            difference[Z_AXIS] / segments,
            difference[E_AXIS] / segments
          };

    // SERIAL_ECHOPAIR("mm=", cartesian_mm);
    // SERIAL_ECHOPAIR(" seconds=", seconds);
    // SERIAL_ECHOLNPAIR(" segments=", segments);

    // Drop one segment so the last move is to the exact target.
    // If there's only 1 segment, loops will be skipped entirely.
    --segments;

    // Using "raw" coordinates saves 6 float subtractions
    // per segment, saving valuable CPU cycles

    #if ENABLED(USE_RAW_KINEMATICS)

      // Get the raw current position as starting point
      float raw[XYZE] = {
        RAW_CURRENT_POSITION(X_AXIS),
        RAW_CURRENT_POSITION(Y_AXIS),
        RAW_CURRENT_POSITION(Z_AXIS),
        current_position[E_AXIS]
      };

      #define DELTA_VAR raw

      // Delta can inline its kinematics
      #if ENABLED(DELTA)
        #define DELTA_IK() DELTA_RAW_IK()
      #else
        #define DELTA_IK() inverse_kinematics(raw)
      #endif

    #else

      // Get the logical current position as starting point
      float logical[XYZE];
      memcpy(logical, current_position, sizeof(logical));

      #define DELTA_VAR logical

      // Delta can inline its kinematics
      #if ENABLED(DELTA)
        #define DELTA_IK() DELTA_LOGICAL_IK()
      #else
        #define DELTA_IK() inverse_kinematics(logical)
      #endif

    #endif

    #if ENABLED(USE_DELTA_IK_INTERPOLATION)

      // Only interpolate XYZ. Advance E normally.
      #define DELTA_NEXT(ADDEND) LOOP_XYZ(i) DELTA_VAR[i] += ADDEND;

      // Get the starting delta if interpolation is possible
      if (segments >= 2) DELTA_IK();

      // Loop using decrement
      for (uint16_t s = segments + 1; --s;) {
        // Are there at least 2 moves left?
        if (s >= 2) {
          // Save the previous delta for interpolation
          float prev_delta[ABC] = { delta[A_AXIS], delta[B_AXIS], delta[C_AXIS] };

          // Get the delta 2 segments ahead (rather than the next)
          DELTA_NEXT(segment_distance[i] + segment_distance[i]);

          // Advance E normally
          DELTA_VAR[E_AXIS] += segment_distance[E_AXIS];

          // Get the exact delta for the move after this
          DELTA_IK();

          // Move to the interpolated delta position first
          planner.buffer_line(
            (prev_delta[A_AXIS] + delta[A_AXIS]) * 0.5,
            (prev_delta[B_AXIS] + delta[B_AXIS]) * 0.5,
            (prev_delta[C_AXIS] + delta[C_AXIS]) * 0.5,
            DELTA_VAR[E_AXIS], _feedrate_mm_s, active_extruder
          );

          // Advance E once more for the next move
          DELTA_VAR[E_AXIS] += segment_distance[E_AXIS];

          // Do an extra decrement of the loop
          --s;
        }
        else {
          // Get the last segment delta. (Used when segments is odd)
          DELTA_NEXT(segment_distance[i]);
          DELTA_VAR[E_AXIS] += segment_distance[E_AXIS];
          DELTA_IK();
        }

        // Move to the non-interpolated position
        planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], DELTA_VAR[E_AXIS], _feedrate_mm_s, active_extruder);
      }

    #else

      #define DELTA_NEXT(ADDEND) LOOP_XYZE(i) DELTA_VAR[i] += ADDEND;

      // For non-interpolated delta calculate every segment
      for (uint16_t s = segments + 1; --s;) {
        DELTA_NEXT(segment_distance[i]);
        DELTA_IK();
        planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], DELTA_VAR[E_AXIS], _feedrate_mm_s, active_extruder);
      }

    #endif

    // Since segment_distance is only approximate,
    // the final move must be to the exact destination.
    inverse_kinematics(ltarget);
    planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], ltarget[E_AXIS], _feedrate_mm_s, active_extruder);
    return true;
  }

#else

  /**
   * Prepare a linear move in a Cartesian setup.
   * If Mesh Bed Leveling is enabled, perform a mesh move.
   */
  inline bool prepare_move_to_destination_cartesian() {
    // Do not use feedrate_percentage for E or Z only moves
    if (current_position[X_AXIS] == destination[X_AXIS] && current_position[Y_AXIS] == destination[Y_AXIS]) {
      line_to_destination();
    }
    else {
      #if ENABLED(MESH_BED_LEVELING)
        if (mbl.active()) {
          mesh_line_to_destination(MMS_SCALED(feedrate_mm_s));
          return false;
        }
        else
      #endif
          line_to_destination(MMS_SCALED(feedrate_mm_s));
    }
    return true;
  }

#endif // !IS_KINEMATIC

#if ENABLED(DUAL_X_CARRIAGE)

  /**
   * Prepare a linear move in a dual X axis setup
   */
  inline bool prepare_move_to_destination_dualx() {
    if (active_extruder_parked) {
      if (dual_x_carriage_mode == DXC_DUPLICATION_MODE && active_extruder == 0) {
        // move duplicate extruder into correct duplication position.
        planner.set_position_mm(
          LOGICAL_X_POSITION(inactive_extruder_x_pos),
          current_position[Y_AXIS],
          current_position[Z_AXIS],
          current_position[E_AXIS]
        );
        planner.buffer_line(current_position[X_AXIS] + duplicate_extruder_x_offset,
                         current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], planner.max_feedrate_mm_s[X_AXIS], 1);
        SYNC_PLAN_POSITION_KINEMATIC();
        stepper.synchronize();
        extruder_duplication_enabled = true;
        active_extruder_parked = false;
      }
      else if (dual_x_carriage_mode == DXC_AUTO_PARK_MODE) { // handle unparking of head
        if (current_position[E_AXIS] == destination[E_AXIS]) {
          // This is a travel move (with no extrusion)
          // Skip it, but keep track of the current position
          // (so it can be used as the start of the next non-travel move)
          if (delayed_move_time != 0xFFFFFFFFUL) {
            set_current_to_destination();
            NOLESS(raised_parked_position[Z_AXIS], destination[Z_AXIS]);
            delayed_move_time = millis();
            return false;
          }
        }
        delayed_move_time = 0;
        // unpark extruder: 1) raise, 2) move into starting XY position, 3) lower
        planner.buffer_line(raised_parked_position[X_AXIS], raised_parked_position[Y_AXIS], raised_parked_position[Z_AXIS], current_position[E_AXIS], planner.max_feedrate_mm_s[Z_AXIS], active_extruder);
        planner.buffer_line(current_position[X_AXIS], current_position[Y_AXIS], raised_parked_position[Z_AXIS], current_position[E_AXIS], PLANNER_XY_FEEDRATE(), active_extruder);
        planner.buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], planner.max_feedrate_mm_s[Z_AXIS], active_extruder);
        active_extruder_parked = false;
      }
    }
    return true;
  }

#endif // DUAL_X_CARRIAGE

/**
 * Prepare a single move and get ready for the next one
 *
 * This may result in several calls to planner.buffer_line to
 * do smaller moves for DELTA, SCARA, mesh moves, etc.
 */
void prepare_move_to_destination() {
  clamp_to_software_endstops(destination);
  refresh_cmd_timeout();

  #if ENABLED(PREVENT_COLD_EXTRUSION)

    if (!DEBUGGING(DRYRUN)) {
      if (destination[E_AXIS] != current_position[E_AXIS]) {
        if (thermalManager.tooColdToExtrude(active_extruder)) {
          current_position[E_AXIS] = destination[E_AXIS]; // Behave as if the move really took place, but ignore E part
          SERIAL_ECHO_START;
          SERIAL_ECHOLNPGM(MSG_ERR_COLD_EXTRUDE_STOP);
        }
        #if ENABLED(PREVENT_LENGTHY_EXTRUDE)
          if (labs(destination[E_AXIS] - current_position[E_AXIS]) > EXTRUDE_MAXLENGTH) {
            current_position[E_AXIS] = destination[E_AXIS]; // Behave as if the move really took place, but ignore E part
            SERIAL_ECHO_START;
            SERIAL_ECHOLNPGM(MSG_ERR_LONG_EXTRUDE_STOP);
          }
        #endif
      }
    }

  #endif

  #if IS_KINEMATIC
    if (!prepare_kinematic_move_to(destination)) return;
  #else
    #if ENABLED(DUAL_X_CARRIAGE)
      if (!prepare_move_to_destination_dualx()) return;
    #endif
    if (!prepare_move_to_destination_cartesian()) return;
  #endif

  set_current_to_destination();
}

#if ENABLED(ARC_SUPPORT)
  /**
   * Plan an arc in 2 dimensions
   *
   * The arc is approximated by generating many small linear segments.
   * The length of each segment is configured in MM_PER_ARC_SEGMENT (Default 1mm)
   * Arcs should only be made relatively large (over 5mm), as larger arcs with
   * larger segments will tend to be more efficient. Your slicer should have
   * options for G2/G3 arc generation. In future these options may be GCode tunable.
   */
  void plan_arc(
    float logical[NUM_AXIS], // Destination position
    float* offset,           // Center of rotation relative to current_position
    uint8_t clockwise        // Clockwise?
  ) {

    float radius = HYPOT(offset[X_AXIS], offset[Y_AXIS]),
          center_X = current_position[X_AXIS] + offset[X_AXIS],
          center_Y = current_position[Y_AXIS] + offset[Y_AXIS],
          linear_travel = logical[Z_AXIS] - current_position[Z_AXIS],
          extruder_travel = logical[E_AXIS] - current_position[E_AXIS],
          r_X = -offset[X_AXIS],  // Radius vector from center to current location
          r_Y = -offset[Y_AXIS],
          rt_X = logical[X_AXIS] - center_X,
          rt_Y = logical[Y_AXIS] - center_Y;

    // CCW angle of rotation between position and target from the circle center. Only one atan2() trig computation required.
    float angular_travel = atan2(r_X * rt_Y - r_Y * rt_X, r_X * rt_X + r_Y * rt_Y);
    if (angular_travel < 0) angular_travel += RADIANS(360);
    if (clockwise) angular_travel -= RADIANS(360);

    // Make a circle if the angular rotation is 0
    if (angular_travel == 0 && current_position[X_AXIS] == logical[X_AXIS] && current_position[Y_AXIS] == logical[Y_AXIS])
      angular_travel += RADIANS(360);

    float mm_of_travel = HYPOT(angular_travel * radius, fabs(linear_travel));
    if (mm_of_travel < 0.001) return;
    uint16_t segments = floor(mm_of_travel / (MM_PER_ARC_SEGMENT));
    if (segments == 0) segments = 1;

    float theta_per_segment = angular_travel / segments;
    float linear_per_segment = linear_travel / segments;
    float extruder_per_segment = extruder_travel / segments;

    /**
     * Vector rotation by transformation matrix: r is the original vector, r_T is the rotated vector,
     * and phi is the angle of rotation. Based on the solution approach by Jens Geisler.
     *     r_T = [cos(phi) -sin(phi);
     *            sin(phi)  cos(phi] * r ;
     *
     * For arc generation, the center of the circle is the axis of rotation and the radius vector is
     * defined from the circle center to the initial position. Each line segment is formed by successive
     * vector rotations. This requires only two cos() and sin() computations to form the rotation
     * matrix for the duration of the entire arc. Error may accumulate from numerical round-off, since
     * all double numbers are single precision on the Arduino. (True double precision will not have
     * round off issues for CNC applications.) Single precision error can accumulate to be greater than
     * tool precision in some cases. Therefore, arc path correction is implemented.
     *
     * Small angle approximation may be used to reduce computation overhead further. This approximation
     * holds for everything, but very small circles and large MM_PER_ARC_SEGMENT values. In other words,
     * theta_per_segment would need to be greater than 0.1 rad and N_ARC_CORRECTION would need to be large
     * to cause an appreciable drift error. N_ARC_CORRECTION~=25 is more than small enough to correct for
     * numerical drift error. N_ARC_CORRECTION may be on the order a hundred(s) before error becomes an
     * issue for CNC machines with the single precision Arduino calculations.
     *
     * This approximation also allows plan_arc to immediately insert a line segment into the planner
     * without the initial overhead of computing cos() or sin(). By the time the arc needs to be applied
     * a correction, the planner should have caught up to the lag caused by the initial plan_arc overhead.
     * This is important when there are successive arc motions.
     */
    // Vector rotation matrix values
    float cos_T = 1 - 0.5 * sq(theta_per_segment); // Small angle approximation
    float sin_T = theta_per_segment;

    float arc_target[NUM_AXIS];
    float sin_Ti, cos_Ti, r_new_Y;
    uint16_t i;
    int8_t count = 0;

    // Initialize the linear axis
    arc_target[Z_AXIS] = current_position[Z_AXIS];

    // Initialize the extruder axis
    arc_target[E_AXIS] = current_position[E_AXIS];

    float fr_mm_s = MMS_SCALED(feedrate_mm_s);

    millis_t next_idle_ms = millis() + 200UL;

    for (i = 1; i < segments; i++) { // Iterate (segments-1) times

      thermalManager.manage_heater();
      millis_t now = millis();
      if (ELAPSED(now, next_idle_ms)) {
        next_idle_ms = now + 200UL;
        idle();
      }

      if (++count < N_ARC_CORRECTION) {
        // Apply vector rotation matrix to previous r_X / 1
        r_new_Y = r_X * sin_T + r_Y * cos_T;
        r_X = r_X * cos_T - r_Y * sin_T;
        r_Y = r_new_Y;
      }
      else {
        // Arc correction to radius vector. Computed only every N_ARC_CORRECTION increments.
        // Compute exact location by applying transformation matrix from initial radius vector(=-offset).
        // To reduce stuttering, the sin and cos could be computed at different times.
        // For now, compute both at the same time.
        cos_Ti = cos(i * theta_per_segment);
        sin_Ti = sin(i * theta_per_segment);
        r_X = -offset[X_AXIS] * cos_Ti + offset[Y_AXIS] * sin_Ti;
        r_Y = -offset[X_AXIS] * sin_Ti - offset[Y_AXIS] * cos_Ti;
        count = 0;
      }

      // Update arc_target location
      arc_target[X_AXIS] = center_X + r_X;
      arc_target[Y_AXIS] = center_Y + r_Y;
      arc_target[Z_AXIS] += linear_per_segment;
      arc_target[E_AXIS] += extruder_per_segment;

      clamp_to_software_endstops(arc_target);

      #if IS_KINEMATIC
        inverse_kinematics(arc_target);
        planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], arc_target[E_AXIS], fr_mm_s, active_extruder);
      #else
        planner.buffer_line(arc_target[X_AXIS], arc_target[Y_AXIS], arc_target[Z_AXIS], arc_target[E_AXIS], fr_mm_s, active_extruder);
      #endif
    }

    // Ensure last segment arrives at target location.
    #if IS_KINEMATIC
      inverse_kinematics(logical);
      planner.buffer_line(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], logical[E_AXIS], fr_mm_s, active_extruder);
    #else
      planner.buffer_line(logical[X_AXIS], logical[Y_AXIS], logical[Z_AXIS], logical[E_AXIS], fr_mm_s, active_extruder);
    #endif

    // As far as the parser is concerned, the position is now == target. In reality the
    // motion control system might still be processing the action and the real tool position
    // in any intermediate location.
    set_current_to_destination();
  }
#endif

#if ENABLED(BEZIER_CURVE_SUPPORT)

  void plan_cubic_move(const float offset[4]) {
    cubic_b_spline(current_position, destination, offset, MMS_SCALED(feedrate_mm_s), active_extruder);

    // As far as the parser is concerned, the position is now == destination. In reality the
    // motion control system might still be processing the action and the real tool position
    // in any intermediate location.
    set_current_to_destination();
  }

#endif // BEZIER_CURVE_SUPPORT

#if HAS_CONTROLLERFAN

  void controllerFan() {
    static millis_t lastMotorOn = 0; // Last time a motor was turned on
    static millis_t nextMotorCheck = 0; // Last time the state was checked
    millis_t ms = millis();
    if (ELAPSED(ms, nextMotorCheck)) {
      nextMotorCheck = ms + 2500UL; // Not a time critical function, so only check every 2.5s
      if (X_ENABLE_READ == X_ENABLE_ON || Y_ENABLE_READ == Y_ENABLE_ON || Z_ENABLE_READ == Z_ENABLE_ON || thermalManager.soft_pwm_bed > 0
          || E0_ENABLE_READ == E_ENABLE_ON // If any of the drivers are enabled...
          #if E_STEPPERS > 1
            || E1_ENABLE_READ == E_ENABLE_ON
            #if HAS_X2_ENABLE
              || X2_ENABLE_READ == X_ENABLE_ON
            #endif
            #if E_STEPPERS > 2
              || E2_ENABLE_READ == E_ENABLE_ON
              #if E_STEPPERS > 3
                || E3_ENABLE_READ == E_ENABLE_ON
              #endif
            #endif
          #endif
      ) {
        lastMotorOn = ms; //... set time to NOW so the fan will turn on
      }

      // Fan off if no steppers have been enabled for CONTROLLERFAN_SECS seconds
      uint8_t speed = (!lastMotorOn || ELAPSED(ms, lastMotorOn + (CONTROLLERFAN_SECS) * 1000UL)) ? 0 : CONTROLLERFAN_SPEED;

      // allows digital or PWM fan output to be used (see M42 handling)
      digitalWrite(CONTROLLERFAN_PIN, speed);
      analogWrite(CONTROLLERFAN_PIN, speed);
    }
  }

#endif // HAS_CONTROLLERFAN

#if ENABLED(MORGAN_SCARA)

  /**
   * Morgan SCARA Forward Kinematics. Results in cartes[].
   * Maths and first version by QHARLEY.
   * Integrated into Marlin and slightly restructured by Joachim Cerny.
   */
  void forward_kinematics_SCARA(const float &a, const float &b) {

    float a_sin = sin(RADIANS(a)) * L1,
          a_cos = cos(RADIANS(a)) * L1,
          b_sin = sin(RADIANS(b)) * L2,
          b_cos = cos(RADIANS(b)) * L2;

    cartes[X_AXIS] = a_cos + b_cos + SCARA_OFFSET_X;  //theta
    cartes[Y_AXIS] = a_sin + b_sin + SCARA_OFFSET_Y;  //theta+phi

    /*
      SERIAL_ECHOPAIR("SCARA FK Angle a=", a);
      SERIAL_ECHOPAIR(" b=", b);
      SERIAL_ECHOPAIR(" a_sin=", a_sin);
      SERIAL_ECHOPAIR(" a_cos=", a_cos);
      SERIAL_ECHOPAIR(" b_sin=", b_sin);
      SERIAL_ECHOLNPAIR(" b_cos=", b_cos);
      SERIAL_ECHOPAIR(" cartes[X_AXIS]=", cartes[X_AXIS]);
      SERIAL_ECHOLNPAIR(" cartes[Y_AXIS]=", cartes[Y_AXIS]);
    //*/
  }

  /**
   * Morgan SCARA Inverse Kinematics. Results in delta[].
   *
   * See http://forums.reprap.org/read.php?185,283327
   * 
   * Maths and first version by QHARLEY.
   * Integrated into Marlin and slightly restructured by Joachim Cerny.
   */
  void inverse_kinematics(const float logical[XYZ]) {

    static float C2, S2, SK1, SK2, THETA, PSI;

    float sx = RAW_X_POSITION(logical[X_AXIS]) - SCARA_OFFSET_X,  // Translate SCARA to standard X Y
          sy = RAW_Y_POSITION(logical[Y_AXIS]) - SCARA_OFFSET_Y;  // With scaling factor.

    if (L1 == L2)
      C2 = HYPOT2(sx, sy) / L1_2_2 - 1;
    else
      C2 = (HYPOT2(sx, sy) - (L1_2 + L2_2)) / (2.0 * L1 * L2);

    S2 = sqrt(sq(C2) - 1);

    // Unrotated Arm1 plus rotated Arm2 gives the distance from Center to End
    SK1 = L1 + L2 * C2;

    // Rotated Arm2 gives the distance from Arm1 to Arm2
    SK2 = L2 * S2;

    // Angle of Arm1 is the difference between Center-to-End angle and the Center-to-Elbow
    THETA = atan2(SK1, SK2) - atan2(sx, sy);

    // Angle of Arm2
    PSI = atan2(S2, C2);

    delta[A_AXIS] = DEGREES(THETA);        // theta is support arm angle
    delta[B_AXIS] = DEGREES(THETA + PSI);  // equal to sub arm angle (inverted motor)
    delta[C_AXIS] = logical[Z_AXIS];

    /*
      DEBUG_POS("SCARA IK", logical);
      DEBUG_POS("SCARA IK", delta);
      SERIAL_ECHOPAIR("  SCARA (x,y) ", sx);
      SERIAL_ECHOPAIR(",", sy);
      SERIAL_ECHOPAIR(" C2=", C2);
      SERIAL_ECHOPAIR(" S2=", S2);
      SERIAL_ECHOPAIR(" Theta=", THETA);
      SERIAL_ECHOLNPAIR(" Phi=", PHI);
    //*/
  }

#endif // MORGAN_SCARA

#if ENABLED(TEMP_STAT_LEDS)

  static bool red_led = false;
  static millis_t next_status_led_update_ms = 0;

  void handle_status_leds(void) {
    if (ELAPSED(millis(), next_status_led_update_ms)) {
      next_status_led_update_ms += 500; // Update every 0.5s
      float max_temp = 0.0;
      #if HAS_TEMP_BED
        max_temp = MAX3(max_temp, thermalManager.degTargetBed(), thermalManager.degBed());
      #endif
      HOTEND_LOOP() {
        max_temp = MAX3(max_temp, thermalManager.degHotend(e), thermalManager.degTargetHotend(e));
      }
      bool new_led = (max_temp > 55.0) ? true : (max_temp < 54.0) ? false : red_led;
      if (new_led != red_led) {
        red_led = new_led;
        WRITE(STAT_LED_RED_PIN, new_led ? HIGH : LOW);
        WRITE(STAT_LED_BLUE_PIN, new_led ? LOW : HIGH);
      }
    }
  }

#endif

#if ENABLED(FILAMENT_RUNOUT_SENSOR)

  void handle_filament_runout() {
    if (!filament_ran_out) {
      filament_ran_out = true;
      enqueue_and_echo_commands_P(PSTR(FILAMENT_RUNOUT_SCRIPT));
      stepper.synchronize();
    }
  }

#endif // FILAMENT_RUNOUT_SENSOR

#if ENABLED(FAST_PWM_FAN)

  void setPwmFrequency(uint8_t pin, int val) {
    val &= 0x07;
    switch (digitalPinToTimer(pin)) {
      #if defined(TCCR0A)
        case TIMER0A:
        case TIMER0B:
          // TCCR0B &= ~(_BV(CS00) | _BV(CS01) | _BV(CS02));
          // TCCR0B |= val;
          break;
      #endif
      #if defined(TCCR1A)
        case TIMER1A:
        case TIMER1B:
          // TCCR1B &= ~(_BV(CS10) | _BV(CS11) | _BV(CS12));
          // TCCR1B |= val;
          break;
      #endif
      #if defined(TCCR2)
        case TIMER2:
        case TIMER2:
          TCCR2 &= ~(_BV(CS10) | _BV(CS11) | _BV(CS12));
          TCCR2 |= val;
          break;
      #endif
      #if defined(TCCR2A)
        case TIMER2A:
        case TIMER2B:
          TCCR2B &= ~(_BV(CS20) | _BV(CS21) | _BV(CS22));
          TCCR2B |= val;
          break;
      #endif
      #if defined(TCCR3A)
        case TIMER3A:
        case TIMER3B:
        case TIMER3C:
          TCCR3B &= ~(_BV(CS30) | _BV(CS31) | _BV(CS32));
          TCCR3B |= val;
          break;
      #endif
      #if defined(TCCR4A)
        case TIMER4A:
        case TIMER4B:
        case TIMER4C:
          TCCR4B &= ~(_BV(CS40) | _BV(CS41) | _BV(CS42));
          TCCR4B |= val;
          break;
      #endif
      #if defined(TCCR5A)
        case TIMER5A:
        case TIMER5B:
        case TIMER5C:
          TCCR5B &= ~(_BV(CS50) | _BV(CS51) | _BV(CS52));
          TCCR5B |= val;
          break;
      #endif
    }
  }

#endif // FAST_PWM_FAN

float calculate_volumetric_multiplier(float diameter) {
  if (!volumetric_enabled || diameter == 0) return 1.0;
  float d2 = diameter * 0.5;
  return 1.0 / (M_PI * d2 * d2);
}

void calculate_volumetric_multipliers() {
  for (uint8_t i = 0; i < COUNT(filament_size); i++)
    volumetric_multiplier[i] = calculate_volumetric_multiplier(filament_size[i]);
}

void enable_all_steppers() {
  enable_x();
  enable_y();
  enable_z();
  enable_e0();
  enable_e1();
  enable_e2();
  enable_e3();
}

void disable_all_steppers() {
  disable_x();
  disable_y();
  disable_z();
  disable_e0();
  disable_e1();
  disable_e2();
  disable_e3();
}

/**
 * Manage several activities:
 *  - Check for Filament Runout
 *  - Keep the command buffer full
 *  - Check for maximum inactive time between commands
 *  - Check for maximum inactive time between stepper commands
 *  - Check if pin CHDK needs to go LOW
 *  - Check for KILL button held down
 *  - Check for HOME button held down
 *  - Check if cooling fan needs to be switched on
 *  - Check if an idle but hot extruder needs filament extruded (EXTRUDER_RUNOUT_PREVENT)
 */
void manage_inactivity(bool ignore_stepper_queue/*=false*/) {

  #if ENABLED(FILAMENT_RUNOUT_SENSOR)
    if ((IS_SD_PRINTING || print_job_timer.isRunning()) && !(READ(FIL_RUNOUT_PIN) ^ FIL_RUNOUT_INVERTING))
      handle_filament_runout();
  #endif

  if (commands_in_queue < BUFSIZE) get_available_commands();

  millis_t ms = millis();

  if (max_inactive_time && ELAPSED(ms, previous_cmd_ms + max_inactive_time)) kill(PSTR(MSG_KILLED));

  if (stepper_inactive_time && ELAPSED(ms, previous_cmd_ms + stepper_inactive_time)
      && !ignore_stepper_queue && !planner.blocks_queued()) {
    #if ENABLED(DISABLE_INACTIVE_X)
      disable_x();
    #endif
    #if ENABLED(DISABLE_INACTIVE_Y)
      disable_y();
    #endif
    #if ENABLED(DISABLE_INACTIVE_Z)
      disable_z();
    #endif
    #if ENABLED(DISABLE_INACTIVE_E)
      disable_e0();
      disable_e1();
      disable_e2();
      disable_e3();
    #endif
  }

  #ifdef CHDK // Check if pin should be set to LOW after M240 set it to HIGH
    if (chdkActive && PENDING(ms, chdkHigh + CHDK_DELAY)) {
      chdkActive = false;
      WRITE(CHDK, LOW);
    }
  #endif

  #if HAS_KILL

    // Check if the kill button was pressed and wait just in case it was an accidental
    // key kill key press
    // -------------------------------------------------------------------------------
    static int killCount = 0;   // make the inactivity button a bit less responsive
    const int KILL_DELAY = 750;
    if (!READ(KILL_PIN))
      killCount++;
    else if (killCount > 0)
      killCount--;

    // Exceeded threshold and we can confirm that it was not accidental
    // KILL the machine
    // ----------------------------------------------------------------
    if (killCount >= KILL_DELAY) kill(PSTR(MSG_KILLED));
  #endif

  #if HAS_HOME
    // Check to see if we have to home, use poor man's debouncer
    // ---------------------------------------------------------
    static int homeDebounceCount = 0;   // poor man's debouncing count
    const int HOME_DEBOUNCE_DELAY = 2500;
    if (!READ(HOME_PIN)) {
      if (!homeDebounceCount) {
        enqueue_and_echo_commands_P(PSTR("G28"));
        LCD_MESSAGEPGM(MSG_AUTO_HOME);
      }
      if (homeDebounceCount < HOME_DEBOUNCE_DELAY)
        homeDebounceCount++;
      else
        homeDebounceCount = 0;
    }
  #endif

  #if HAS_CONTROLLERFAN
    controllerFan(); // Check if fan should be turned on to cool stepper drivers down
  #endif

  #if ENABLED(EXTRUDER_RUNOUT_PREVENT)
    if (ELAPSED(ms, previous_cmd_ms + (EXTRUDER_RUNOUT_SECONDS) * 1000UL)
      && thermalManager.degHotend(active_extruder) > EXTRUDER_RUNOUT_MINTEMP) {
      bool oldstatus;
      #if ENABLED(SWITCHING_EXTRUDER)
        oldstatus = E0_ENABLE_READ;
        enable_e0();
      #else // !SWITCHING_EXTRUDER
        switch (active_extruder) {
          case 0:
            oldstatus = E0_ENABLE_READ;
            enable_e0();
            break;
          #if E_STEPPERS > 1
            case 1:
              oldstatus = E1_ENABLE_READ;
              enable_e1();
              break;
            #if E_STEPPERS > 2
              case 2:
                oldstatus = E2_ENABLE_READ;
                enable_e2();
                break;
              #if E_STEPPERS > 3
                case 3:
                  oldstatus = E3_ENABLE_READ;
                  enable_e3();
                  break;
              #endif
            #endif
          #endif
        }
      #endif // !SWITCHING_EXTRUDER

      previous_cmd_ms = ms; // refresh_cmd_timeout()
      planner.buffer_line(
        current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS],
        current_position[E_AXIS] + EXTRUDER_RUNOUT_EXTRUDE,
        MMM_TO_MMS(EXTRUDER_RUNOUT_SPEED), active_extruder
      );
      stepper.synchronize();
      planner.set_e_position_mm(current_position[E_AXIS]);
      #if ENABLED(SWITCHING_EXTRUDER)
        E0_ENABLE_WRITE(oldstatus);
      #else
        switch (active_extruder) {
          case 0:
            E0_ENABLE_WRITE(oldstatus);
            break;
          #if E_STEPPERS > 1
            case 1:
              E1_ENABLE_WRITE(oldstatus);
              break;
            #if E_STEPPERS > 2
              case 2:
                E2_ENABLE_WRITE(oldstatus);
                break;
              #if E_STEPPERS > 3
                case 3:
                  E3_ENABLE_WRITE(oldstatus);
                  break;
              #endif
            #endif
          #endif
        }
      #endif // !SWITCHING_EXTRUDER
    }
  #endif // EXTRUDER_RUNOUT_PREVENT

  #if ENABLED(DUAL_X_CARRIAGE)
    // handle delayed move timeout
    if (delayed_move_time && ELAPSED(ms, delayed_move_time + 1000UL) && IsRunning()) {
      // travel moves have been received so enact them
      delayed_move_time = 0xFFFFFFFFUL; // force moves to be done
      set_destination_to_current();
      prepare_move_to_destination();
    }
  #endif

  #if ENABLED(TEMP_STAT_LEDS)
    handle_status_leds();
  #endif

  planner.check_axes_activity();
}

/**
 * Standard idle routine keeps the machine alive
 */
void idle(
  #if ENABLED(FILAMENT_CHANGE_FEATURE)
    bool no_stepper_sleep/*=false*/
  #endif
) {
  lcd_update();
  host_keepalive();
  manage_inactivity(
    #if ENABLED(FILAMENT_CHANGE_FEATURE)
      no_stepper_sleep
    #endif
  );

  thermalManager.manage_heater();

  #if ENABLED(PRINTCOUNTER)
    print_job_timer.tick();
  #endif

  #if HAS_BUZZER && PIN_EXISTS(BEEPER)
    buzzer.tick();
  #endif
}

/**
 * Kill all activity and lock the machine.
 * After this the machine will need to be reset.
 */
void kill(const char* lcd_msg) {
  SERIAL_ERROR_START;
  SERIAL_ERRORLNPGM(MSG_ERR_KILLED);

  #if ENABLED(ULTRA_LCD)
    kill_screen(lcd_msg);
  #else
    UNUSED(lcd_msg);
  #endif

  delay(500); // Wait a short time

  cli(); // Stop interrupts
  thermalManager.disable_all_heaters();
  disable_all_steppers();

  #if HAS_POWER_SWITCH
    pinMode(PS_ON_PIN, INPUT);
  #endif

  suicide();
  while (1) {
    #if ENABLED(USE_WATCHDOG)
      watchdog_reset();
    #endif
  } // Wait for reset
}

/**
 * Turn off heaters and stop the print in progress
 * After a stop the machine may be resumed with M999
 */
void stop() {
  thermalManager.disable_all_heaters();
  if (IsRunning()) {
    Running = false;
    Stopped_gcode_LastN = gcode_LastN; // Save last g_code for restart
    SERIAL_ERROR_START;
    SERIAL_ERRORLNPGM(MSG_ERR_STOPPED);
    LCD_MESSAGEPGM(MSG_STOPPED);
  }
}

/**
 * Marlin entry-point: Set up before the program loop
 *  - Set up the kill pin, filament runout, power hold
 *  - Start the serial port
 *  - Print startup messages and diagnostics
 *  - Get EEPROM or default settings
 *  - Initialize managers for:
 *    • temperature
 *    • planner
 *    • watchdog
 *    • stepper
 *    • photo pin
 *    • servos
 *    • LCD controller
 *    • Digipot I2C
 *    • Z probe sled
 *    • status LEDs
 */
void setup() {

  #ifdef DISABLE_JTAG
    // Disable JTAG on AT90USB chips to free up pins for IO
    MCUCR = 0x80;
    MCUCR = 0x80;
  #endif

  #if ENABLED(FILAMENT_RUNOUT_SENSOR)
    setup_filrunoutpin();
  #endif

  setup_killpin();

  setup_powerhold();

  #if HAS_STEPPER_RESET
    disableStepperDrivers();
  #endif

  MYSERIAL.begin(BAUDRATE);
  SERIAL_PROTOCOLLNPGM("start");
  SERIAL_ECHO_START;

  // Check startup - does nothing if bootloader sets MCUSR to 0
  byte mcu = MCUSR;
  if (mcu & 1) SERIAL_ECHOLNPGM(MSG_POWERUP);
  if (mcu & 2) SERIAL_ECHOLNPGM(MSG_EXTERNAL_RESET);
  if (mcu & 4) SERIAL_ECHOLNPGM(MSG_BROWNOUT_RESET);
  if (mcu & 8) SERIAL_ECHOLNPGM(MSG_WATCHDOG_RESET);
  if (mcu & 32) SERIAL_ECHOLNPGM(MSG_SOFTWARE_RESET);
  MCUSR = 0;

  SERIAL_ECHOPGM(MSG_MARLIN);
  SERIAL_CHAR(' ');
  SERIAL_ECHOLNPGM(SHORT_BUILD_VERSION);
  SERIAL_EOL;

  #if defined(STRING_DISTRIBUTION_DATE) && defined(STRING_CONFIG_H_AUTHOR)
    SERIAL_ECHO_START;
    SERIAL_ECHOPGM(MSG_CONFIGURATION_VER);
    SERIAL_ECHOPGM(STRING_DISTRIBUTION_DATE);
    SERIAL_ECHOLNPGM(MSG_AUTHOR STRING_CONFIG_H_AUTHOR);
    SERIAL_ECHOLNPGM("Compiled: " __DATE__);
  #endif

  SERIAL_ECHO_START;
  SERIAL_ECHOPAIR(MSG_FREE_MEMORY, freeMemory());
  SERIAL_ECHOLNPAIR(MSG_PLANNER_BUFFER_BYTES, (int)sizeof(block_t)*BLOCK_BUFFER_SIZE);

  // Send "ok" after commands by default
  for (int8_t i = 0; i < BUFSIZE; i++) send_ok[i] = true;

  // Load data from EEPROM if available (or use defaults)
  // This also updates variables in the planner, elsewhere
  Config_RetrieveSettings();

  // Initialize current position based on home_offset
  memcpy(current_position, home_offset, sizeof(home_offset));

  // Vital to init stepper/planner equivalent for current_position
  SYNC_PLAN_POSITION_KINEMATIC();

  thermalManager.init();    // Initialize temperature loop

  #if ENABLED(USE_WATCHDOG)
    watchdog_init();
  #endif

  stepper.init();    // Initialize stepper, this enables interrupts!
  setup_photpin();
  servo_init();

  #if HAS_BED_PROBE
    endstops.enable_z_probe(false);
  #endif

  #if HAS_CONTROLLERFAN
    SET_OUTPUT(CONTROLLERFAN_PIN); //Set pin used for driver cooling fan
  #endif

  #if HAS_STEPPER_RESET
    enableStepperDrivers();
  #endif

  #if ENABLED(DIGIPOT_I2C)
    digipot_i2c_init();
  #endif

  #if ENABLED(DAC_STEPPER_CURRENT)
    dac_init();
  #endif

  #if ENABLED(Z_PROBE_SLED) && PIN_EXISTS(SLED)
    pinMode(SLED_PIN, OUTPUT);
    digitalWrite(SLED_PIN, LOW); // turn it off
  #endif // Z_PROBE_SLED

  setup_homepin();

  #if PIN_EXISTS(STAT_LED_RED)
    OUT_WRITE(STAT_LED_RED_PIN, LOW); // turn it off
  #endif

  #if PIN_EXISTS(STAT_LED_BLUE)
    OUT_WRITE(STAT_LED_BLUE_PIN, LOW); // turn it off
  #endif

  lcd_init();
  #if ENABLED(SHOW_BOOTSCREEN)
    #if ENABLED(DOGLCD)
      safe_delay(BOOTSCREEN_TIMEOUT);
    #elif ENABLED(ULTRA_LCD)
      bootscreen();
      lcd_init();
    #endif
  #endif

  #if ENABLED(MIXING_EXTRUDER) && MIXING_VIRTUAL_TOOLS > 1
    // Initialize mixing to 100% color 1
    for (uint8_t i = 0; i < MIXING_STEPPERS; i++)
      mixing_factor[i] = (i == 0) ? 1 : 0;
    for (uint8_t t = 0; t < MIXING_VIRTUAL_TOOLS; t++)
      for (uint8_t i = 0; i < MIXING_STEPPERS; i++)
        mixing_virtual_tool_mix[t][i] = mixing_factor[i];
  #endif

  #if ENABLED(EXPERIMENTAL_I2CBUS) && I2C_SLAVE_ADDRESS > 0
    i2c.onReceive(i2c_on_receive);
    i2c.onRequest(i2c_on_request);
  #endif
}

/**
 * The main Marlin program loop
 *
 *  - Save or log commands to SD
 *  - Process available commands (if not saving)
 *  - Call heater manager
 *  - Call inactivity manager
 *  - Call endstop manager
 *  - Call LCD update
 */
void loop() {
  if (commands_in_queue < BUFSIZE) get_available_commands();

  #if ENABLED(SDSUPPORT)
    card.checkautostart(false);
  #endif

  if (commands_in_queue) {

    #if ENABLED(SDSUPPORT)

      if (card.saving) {
        char* command = command_queue[cmd_queue_index_r];
        if (strstr_P(command, PSTR("M29"))) {
          // M29 closes the file
          card.closefile();
          SERIAL_PROTOCOLLNPGM(MSG_FILE_SAVED);
          ok_to_send();
        }
        else {
          // Write the string from the read buffer to SD
          card.write_command(command);
          if (card.logging)
            process_next_command(); // The card is saving because it's logging
          else
            ok_to_send();
        }
      }
      else
        process_next_command();

    #else

      process_next_command();

    #endif // SDSUPPORT

    // The queue may be reset by a command handler or by code invoked by idle() within a handler
    if (commands_in_queue) {
      --commands_in_queue;
      cmd_queue_index_r = (cmd_queue_index_r + 1) % BUFSIZE;
    }
  }
  endstops.report_state();
  idle();
}