/**
* 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 .
*
*/
/**
* stepper.cpp - A singleton object to execute motion plans using stepper motors
* Marlin Firmware
*
* Derived from Grbl
* Copyright (c) 2009-2011 Simen Svale Skogsrud
*
* Grbl 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.
*
* Grbl 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 Grbl. If not, see .
*/
/* The timer calculations of this module informed by the 'RepRap cartesian firmware' by Zack Smith
and Philipp Tiefenbacher. */
#include "Marlin.h"
#include "stepper.h"
#include "endstops.h"
#include "planner.h"
#include "temperature.h"
#include "ultralcd.h"
#include "language.h"
#include "cardreader.h"
#include "speed_lookuptable.h"
#if HAS_DIGIPOTSS
#include
#endif
Stepper stepper; // Singleton
// public:
block_t* Stepper::current_block = NULL; // A pointer to the block currently being traced
#if ENABLED(ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
bool Stepper::abort_on_endstop_hit = false;
#endif
#if ENABLED(Z_DUAL_ENDSTOPS)
bool Stepper::performing_homing = false;
#endif
// private:
unsigned char Stepper::last_direction_bits = 0; // The next stepping-bits to be output
unsigned int Stepper::cleaning_buffer_counter = 0;
#if ENABLED(Z_DUAL_ENDSTOPS)
bool Stepper::locked_z_motor = false;
bool Stepper::locked_z2_motor = false;
#endif
long Stepper::counter_X = 0,
Stepper::counter_Y = 0,
Stepper::counter_Z = 0,
Stepper::counter_E = 0;
volatile uint32_t Stepper::step_events_completed = 0; // The number of step events executed in the current block
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
unsigned char Stepper::old_OCR0A = 0;
volatile unsigned char Stepper::eISR_Rate = 200; // Keep the ISR at a low rate until needed
#if ENABLED(LIN_ADVANCE)
volatile int Stepper::e_steps[E_STEPPERS];
int Stepper::extruder_advance_k = LIN_ADVANCE_K,
Stepper::final_estep_rate,
Stepper::current_estep_rate[E_STEPPERS],
Stepper::current_adv_steps[E_STEPPERS];
#else
long Stepper::e_steps[E_STEPPERS],
Stepper::final_advance = 0,
Stepper::old_advance = 0,
Stepper::advance_rate,
Stepper::advance;
#endif
#endif
long Stepper::acceleration_time, Stepper::deceleration_time;
volatile long Stepper::count_position[NUM_AXIS] = { 0 };
volatile signed char Stepper::count_direction[NUM_AXIS] = { 1, 1, 1, 1 };
#if ENABLED(MIXING_EXTRUDER)
long Stepper::counter_m[MIXING_STEPPERS];
#endif
unsigned short Stepper::acc_step_rate; // needed for deceleration start point
uint8_t Stepper::step_loops, Stepper::step_loops_nominal;
unsigned short Stepper::OCR1A_nominal;
volatile long Stepper::endstops_trigsteps[XYZ];
#if ENABLED(X_DUAL_STEPPER_DRIVERS)
#define X_APPLY_DIR(v,Q) do{ X_DIR_WRITE(v); X2_DIR_WRITE((v) != INVERT_X2_VS_X_DIR); }while(0)
#define X_APPLY_STEP(v,Q) do{ X_STEP_WRITE(v); X2_STEP_WRITE(v); }while(0)
#elif ENABLED(DUAL_X_CARRIAGE)
#define X_APPLY_DIR(v,ALWAYS) \
if (extruder_duplication_enabled || ALWAYS) { \
X_DIR_WRITE(v); \
X2_DIR_WRITE(v); \
} \
else { \
if (current_block->active_extruder) X2_DIR_WRITE(v); else X_DIR_WRITE(v); \
}
#define X_APPLY_STEP(v,ALWAYS) \
if (extruder_duplication_enabled || ALWAYS) { \
X_STEP_WRITE(v); \
X2_STEP_WRITE(v); \
} \
else { \
if (current_block->active_extruder != 0) X2_STEP_WRITE(v); else X_STEP_WRITE(v); \
}
#else
#define X_APPLY_DIR(v,Q) X_DIR_WRITE(v)
#define X_APPLY_STEP(v,Q) X_STEP_WRITE(v)
#endif
#if ENABLED(Y_DUAL_STEPPER_DRIVERS)
#define Y_APPLY_DIR(v,Q) do{ Y_DIR_WRITE(v); Y2_DIR_WRITE((v) != INVERT_Y2_VS_Y_DIR); }while(0)
#define Y_APPLY_STEP(v,Q) do{ Y_STEP_WRITE(v); Y2_STEP_WRITE(v); }while(0)
#else
#define Y_APPLY_DIR(v,Q) Y_DIR_WRITE(v)
#define Y_APPLY_STEP(v,Q) Y_STEP_WRITE(v)
#endif
#if ENABLED(Z_DUAL_STEPPER_DRIVERS)
#define Z_APPLY_DIR(v,Q) do{ Z_DIR_WRITE(v); Z2_DIR_WRITE(v); }while(0)
#if ENABLED(Z_DUAL_ENDSTOPS)
#define Z_APPLY_STEP(v,Q) \
if (performing_homing) { \
if (Z_HOME_DIR > 0) {\
if (!(TEST(endstops.old_endstop_bits, Z_MAX) && (count_direction[Z_AXIS] > 0)) && !locked_z_motor) Z_STEP_WRITE(v); \
if (!(TEST(endstops.old_endstop_bits, Z2_MAX) && (count_direction[Z_AXIS] > 0)) && !locked_z2_motor) Z2_STEP_WRITE(v); \
} \
else { \
if (!(TEST(endstops.old_endstop_bits, Z_MIN) && (count_direction[Z_AXIS] < 0)) && !locked_z_motor) Z_STEP_WRITE(v); \
if (!(TEST(endstops.old_endstop_bits, Z2_MIN) && (count_direction[Z_AXIS] < 0)) && !locked_z2_motor) Z2_STEP_WRITE(v); \
} \
} \
else { \
Z_STEP_WRITE(v); \
Z2_STEP_WRITE(v); \
}
#else
#define Z_APPLY_STEP(v,Q) do{ Z_STEP_WRITE(v); Z2_STEP_WRITE(v); }while(0)
#endif
#else
#define Z_APPLY_DIR(v,Q) Z_DIR_WRITE(v)
#define Z_APPLY_STEP(v,Q) Z_STEP_WRITE(v)
#endif
#if DISABLED(MIXING_EXTRUDER)
#define E_APPLY_STEP(v,Q) E_STEP_WRITE(v)
#endif
// intRes = longIn1 * longIn2 >> 24
// uses:
// r26 to store 0
// r27 to store bits 16-23 of the 48bit result. The top bit is used to round the two byte result.
// note that the lower two bytes and the upper byte of the 48bit result are not calculated.
// this can cause the result to be out by one as the lower bytes may cause carries into the upper ones.
// B0 A0 are bits 24-39 and are the returned value
// C1 B1 A1 is longIn1
// D2 C2 B2 A2 is longIn2
//
#define MultiU24X32toH16(intRes, longIn1, longIn2) \
asm volatile ( \
"clr r26 \n\t" \
"mul %A1, %B2 \n\t" \
"mov r27, r1 \n\t" \
"mul %B1, %C2 \n\t" \
"movw %A0, r0 \n\t" \
"mul %C1, %C2 \n\t" \
"add %B0, r0 \n\t" \
"mul %C1, %B2 \n\t" \
"add %A0, r0 \n\t" \
"adc %B0, r1 \n\t" \
"mul %A1, %C2 \n\t" \
"add r27, r0 \n\t" \
"adc %A0, r1 \n\t" \
"adc %B0, r26 \n\t" \
"mul %B1, %B2 \n\t" \
"add r27, r0 \n\t" \
"adc %A0, r1 \n\t" \
"adc %B0, r26 \n\t" \
"mul %C1, %A2 \n\t" \
"add r27, r0 \n\t" \
"adc %A0, r1 \n\t" \
"adc %B0, r26 \n\t" \
"mul %B1, %A2 \n\t" \
"add r27, r1 \n\t" \
"adc %A0, r26 \n\t" \
"adc %B0, r26 \n\t" \
"lsr r27 \n\t" \
"adc %A0, r26 \n\t" \
"adc %B0, r26 \n\t" \
"mul %D2, %A1 \n\t" \
"add %A0, r0 \n\t" \
"adc %B0, r1 \n\t" \
"mul %D2, %B1 \n\t" \
"add %B0, r0 \n\t" \
"clr r1 \n\t" \
: \
"=&r" (intRes) \
: \
"d" (longIn1), \
"d" (longIn2) \
: \
"r26" , "r27" \
)
// Some useful constants
#define ENABLE_STEPPER_DRIVER_INTERRUPT() SBI(TIMSK1, OCIE1A)
#define DISABLE_STEPPER_DRIVER_INTERRUPT() CBI(TIMSK1, OCIE1A)
/**
* __________________________
* /| |\ _________________ ^
* / | | \ /| |\ |
* / | | \ / | | \ s
* / | | | | | \ p
* / | | | | | \ e
* +-----+------------------------+---+--+---------------+----+ e
* | BLOCK 1 | BLOCK 2 | d
*
* time ----->
*
* The trapezoid is the shape the speed curve over time. It starts at block->initial_rate, accelerates
* first block->accelerate_until step_events_completed, then keeps going at constant speed until
* step_events_completed reaches block->decelerate_after after which it decelerates until the trapezoid generator is reset.
* The slope of acceleration is calculated using v = u + at where t is the accumulated timer values of the steps so far.
*/
void Stepper::wake_up() {
// TCNT1 = 0;
ENABLE_STEPPER_DRIVER_INTERRUPT();
}
/**
* Set the stepper direction of each axis
*
* COREXY: X_AXIS=A_AXIS and Y_AXIS=B_AXIS
* COREXZ: X_AXIS=A_AXIS and Z_AXIS=C_AXIS
* COREYZ: Y_AXIS=B_AXIS and Z_AXIS=C_AXIS
*/
void Stepper::set_directions() {
#define SET_STEP_DIR(AXIS) \
if (motor_direction(AXIS ##_AXIS)) { \
AXIS ##_APPLY_DIR(INVERT_## AXIS ##_DIR, false); \
count_direction[AXIS ##_AXIS] = -1; \
} \
else { \
AXIS ##_APPLY_DIR(!INVERT_## AXIS ##_DIR, false); \
count_direction[AXIS ##_AXIS] = 1; \
}
#if HAS_X_DIR
SET_STEP_DIR(X); // A
#endif
#if HAS_Y_DIR
SET_STEP_DIR(Y); // B
#endif
#if HAS_Z_DIR
SET_STEP_DIR(Z); // C
#endif
#if DISABLED(ADVANCE) && DISABLED(LIN_ADVANCE)
if (motor_direction(E_AXIS)) {
REV_E_DIR();
count_direction[E_AXIS] = -1;
}
else {
NORM_E_DIR();
count_direction[E_AXIS] = 1;
}
#endif // !ADVANCE && !LIN_ADVANCE
}
/**
* Stepper Driver Interrupt
*
* Directly pulses the stepper motors at high frequency.
* Timer 1 runs at a base frequency of 2MHz, with this ISR using OCR1A compare mode.
*
* OCR1A Frequency
* 1 2 MHz
* 50 40 KHz
* 100 20 KHz - capped max rate
* 200 10 KHz - nominal max rate
* 2000 1 KHz - sleep rate
* 4000 500 Hz - init rate
*/
ISR(TIMER1_COMPA_vect) { Stepper::isr(); }
void Stepper::isr() {
if (cleaning_buffer_counter) {
current_block = NULL;
planner.discard_current_block();
#ifdef SD_FINISHED_RELEASECOMMAND
if ((cleaning_buffer_counter == 1) && (SD_FINISHED_STEPPERRELEASE)) enqueue_and_echo_commands_P(PSTR(SD_FINISHED_RELEASECOMMAND));
#endif
cleaning_buffer_counter--;
OCR1A = 200; // Run at max speed - 10 KHz
return;
}
// If there is no current block, attempt to pop one from the buffer
if (!current_block) {
// Anything in the buffer?
current_block = planner.get_current_block();
if (current_block) {
SBI(current_block->flag, BLOCK_BIT_BUSY);
trapezoid_generator_reset();
// Initialize Bresenham counters to 1/2 the ceiling
counter_X = counter_Y = counter_Z = counter_E = -(current_block->step_event_count >> 1);
#if ENABLED(MIXING_EXTRUDER)
MIXING_STEPPERS_LOOP(i)
counter_m[i] = -(current_block->mix_event_count[i] >> 1);
#endif
step_events_completed = 0;
#if ENABLED(Z_LATE_ENABLE)
if (current_block->steps[Z_AXIS] > 0) {
enable_z();
OCR1A = 2000; // Run at slow speed - 1 KHz
return;
}
#endif
// #if ENABLED(ADVANCE)
// e_steps[TOOL_E_INDEX] = 0;
// #endif
}
else {
OCR1A = 2000; // Run at slow speed - 1 KHz
return;
}
}
// Update endstops state, if enabled
if (endstops.enabled
#if HAS_BED_PROBE
|| endstops.z_probe_enabled
#endif
) endstops.update();
// Take multiple steps per interrupt (For high speed moves)
bool all_steps_done = false;
for (int8_t i = 0; i < step_loops; i++) {
#ifndef USBCON
customizedSerial.checkRx(); // Check for serial chars.
#endif
#if ENABLED(LIN_ADVANCE)
counter_E += current_block->steps[E_AXIS];
if (counter_E > 0) {
counter_E -= current_block->step_event_count;
#if DISABLED(MIXING_EXTRUDER)
// Don't step E here for mixing extruder
count_position[E_AXIS] += count_direction[E_AXIS];
motor_direction(E_AXIS) ? --e_steps[TOOL_E_INDEX] : ++e_steps[TOOL_E_INDEX];
#endif
}
#if ENABLED(MIXING_EXTRUDER)
// Step mixing steppers proportionally
const bool dir = motor_direction(E_AXIS);
MIXING_STEPPERS_LOOP(j) {
counter_m[j] += current_block->steps[E_AXIS];
if (counter_m[j] > 0) {
counter_m[j] -= current_block->mix_event_count[j];
dir ? --e_steps[j] : ++e_steps[j];
}
}
#endif
#elif ENABLED(ADVANCE)
// Always count the unified E axis
counter_E += current_block->steps[E_AXIS];
if (counter_E > 0) {
counter_E -= current_block->step_event_count;
#if DISABLED(MIXING_EXTRUDER)
// Don't step E here for mixing extruder
motor_direction(E_AXIS) ? --e_steps[TOOL_E_INDEX] : ++e_steps[TOOL_E_INDEX];
#endif
}
#if ENABLED(MIXING_EXTRUDER)
// Step mixing steppers proportionally
const bool dir = motor_direction(E_AXIS);
MIXING_STEPPERS_LOOP(j) {
counter_m[j] += current_block->steps[E_AXIS];
if (counter_m[j] > 0) {
counter_m[j] -= current_block->mix_event_count[j];
dir ? --e_steps[j] : ++e_steps[j];
}
}
#endif // MIXING_EXTRUDER
#endif // ADVANCE or LIN_ADVANCE
#define _COUNTER(AXIS) counter_## AXIS
#define _APPLY_STEP(AXIS) AXIS ##_APPLY_STEP
#define _INVERT_STEP_PIN(AXIS) INVERT_## AXIS ##_STEP_PIN
// Advance the Bresenham counter; start a pulse if the axis needs a step
#define PULSE_START(AXIS) \
_COUNTER(AXIS) += current_block->steps[_AXIS(AXIS)]; \
if (_COUNTER(AXIS) > 0) { _APPLY_STEP(AXIS)(!_INVERT_STEP_PIN(AXIS),0); }
// Stop an active pulse, reset the Bresenham counter, update the position
#define PULSE_STOP(AXIS) \
if (_COUNTER(AXIS) > 0) { \
_COUNTER(AXIS) -= current_block->step_event_count; \
count_position[_AXIS(AXIS)] += count_direction[_AXIS(AXIS)]; \
_APPLY_STEP(AXIS)(_INVERT_STEP_PIN(AXIS),0); \
}
#define CYCLES_EATEN_BY_CODE 240
// If a minimum pulse time was specified get the CPU clock
#if STEP_PULSE_CYCLES > CYCLES_EATEN_BY_CODE
static uint32_t pulse_start;
pulse_start = TCNT0;
#endif
#if HAS_X_STEP
PULSE_START(X);
#endif
#if HAS_Y_STEP
PULSE_START(Y);
#endif
#if HAS_Z_STEP
PULSE_START(Z);
#endif
// For non-advance use linear interpolation for E also
#if DISABLED(ADVANCE) && DISABLED(LIN_ADVANCE)
#if ENABLED(MIXING_EXTRUDER)
// Keep updating the single E axis
counter_E += current_block->steps[E_AXIS];
// Tick the counters used for this mix
MIXING_STEPPERS_LOOP(j) {
// Step mixing steppers (proportionally)
counter_m[j] += current_block->steps[E_AXIS];
// Step when the counter goes over zero
if (counter_m[j] > 0) En_STEP_WRITE(j, !INVERT_E_STEP_PIN);
}
#else // !MIXING_EXTRUDER
PULSE_START(E);
#endif
#endif // !ADVANCE && !LIN_ADVANCE
// For a minimum pulse time wait before stopping pulses
#if STEP_PULSE_CYCLES > CYCLES_EATEN_BY_CODE
while ((uint32_t)(TCNT0 - pulse_start) < STEP_PULSE_CYCLES - CYCLES_EATEN_BY_CODE) { /* nada */ }
#endif
#if HAS_X_STEP
PULSE_STOP(X);
#endif
#if HAS_Y_STEP
PULSE_STOP(Y);
#endif
#if HAS_Z_STEP
PULSE_STOP(Z);
#endif
#if DISABLED(ADVANCE) && DISABLED(LIN_ADVANCE)
#if ENABLED(MIXING_EXTRUDER)
// Always step the single E axis
if (counter_E > 0) {
counter_E -= current_block->step_event_count;
count_position[E_AXIS] += count_direction[E_AXIS];
}
MIXING_STEPPERS_LOOP(j) {
if (counter_m[j] > 0) {
counter_m[j] -= current_block->mix_event_count[j];
En_STEP_WRITE(j, INVERT_E_STEP_PIN);
}
}
#else // !MIXING_EXTRUDER
PULSE_STOP(E);
#endif
#endif // !ADVANCE && !LIN_ADVANCE
if (++step_events_completed >= current_block->step_event_count) {
all_steps_done = true;
break;
}
}
#if ENABLED(LIN_ADVANCE)
if (current_block->use_advance_lead) {
int delta_adv_steps = (((long)extruder_advance_k * current_estep_rate[TOOL_E_INDEX]) >> 9) - current_adv_steps[TOOL_E_INDEX];
current_adv_steps[TOOL_E_INDEX] += delta_adv_steps;
#if ENABLED(MIXING_EXTRUDER)
// Mixing extruders apply advance lead proportionally
MIXING_STEPPERS_LOOP(j)
e_steps[j] += delta_adv_steps * current_block->step_event_count / current_block->mix_event_count[j];
#else
// For most extruders, advance the single E stepper
e_steps[TOOL_E_INDEX] += delta_adv_steps;
#endif
}
#endif
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
// If we have esteps to execute, fire the next advance_isr "now"
if (e_steps[TOOL_E_INDEX]) OCR0A = TCNT0 + 2;
#endif
// Calculate new timer value
uint16_t timer, step_rate;
if (step_events_completed <= (uint32_t)current_block->accelerate_until) {
MultiU24X32toH16(acc_step_rate, acceleration_time, current_block->acceleration_rate);
acc_step_rate += current_block->initial_rate;
// upper limit
NOMORE(acc_step_rate, current_block->nominal_rate);
// step_rate to timer interval
timer = calc_timer(acc_step_rate);
OCR1A = timer;
acceleration_time += timer;
#if ENABLED(LIN_ADVANCE)
if (current_block->use_advance_lead) {
#if ENABLED(MIXING_EXTRUDER)
MIXING_STEPPERS_LOOP(j)
current_estep_rate[j] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
#else
current_estep_rate[TOOL_E_INDEX] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
#endif
}
#elif ENABLED(ADVANCE)
advance += advance_rate * step_loops;
//NOLESS(advance, current_block->advance);
long advance_whole = advance >> 8,
advance_factor = advance_whole - old_advance;
// Do E steps + advance steps
#if ENABLED(MIXING_EXTRUDER)
// ...for mixing steppers proportionally
MIXING_STEPPERS_LOOP(j)
e_steps[j] += advance_factor * current_block->step_event_count / current_block->mix_event_count[j];
#else
// ...for the active extruder
e_steps[TOOL_E_INDEX] += advance_factor;
#endif
old_advance = advance_whole;
#endif // ADVANCE or LIN_ADVANCE
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
eISR_Rate = (timer >> 3) * step_loops / abs(e_steps[TOOL_E_INDEX]); //>> 3 is divide by 8. Reason: Timer 1 runs at 16/8=2MHz, Timer 0 at 16/64=0.25MHz. ==> 2/0.25=8.
#endif
}
else if (step_events_completed > (uint32_t)current_block->decelerate_after) {
MultiU24X32toH16(step_rate, deceleration_time, current_block->acceleration_rate);
if (step_rate < acc_step_rate) { // Still decelerating?
step_rate = acc_step_rate - step_rate;
NOLESS(step_rate, current_block->final_rate);
}
else
step_rate = current_block->final_rate;
// step_rate to timer interval
timer = calc_timer(step_rate);
OCR1A = timer;
deceleration_time += timer;
#if ENABLED(LIN_ADVANCE)
if (current_block->use_advance_lead) {
#if ENABLED(MIXING_EXTRUDER)
MIXING_STEPPERS_LOOP(j)
current_estep_rate[j] = ((uint32_t)step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
#else
current_estep_rate[TOOL_E_INDEX] = ((uint32_t)step_rate * current_block->e_speed_multiplier8) >> 8;
#endif
}
#elif ENABLED(ADVANCE)
advance -= advance_rate * step_loops;
NOLESS(advance, final_advance);
// Do E steps + advance steps
long advance_whole = advance >> 8,
advance_factor = advance_whole - old_advance;
#if ENABLED(MIXING_EXTRUDER)
MIXING_STEPPERS_LOOP(j)
e_steps[j] += advance_factor * current_block->step_event_count / current_block->mix_event_count[j];
#else
e_steps[TOOL_E_INDEX] += advance_factor;
#endif
old_advance = advance_whole;
#endif // ADVANCE or LIN_ADVANCE
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
eISR_Rate = (timer >> 3) * step_loops / abs(e_steps[TOOL_E_INDEX]);
#endif
}
else {
#if ENABLED(LIN_ADVANCE)
if (current_block->use_advance_lead)
current_estep_rate[TOOL_E_INDEX] = final_estep_rate;
eISR_Rate = (OCR1A_nominal >> 3) * step_loops_nominal / abs(e_steps[TOOL_E_INDEX]);
#endif
OCR1A = OCR1A_nominal;
// ensure we're running at the correct step rate, even if we just came off an acceleration
step_loops = step_loops_nominal;
}
NOLESS(OCR1A, TCNT1 + 16);
// If current block is finished, reset pointer
if (all_steps_done) {
current_block = NULL;
planner.discard_current_block();
}
}
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
// Timer interrupt for E. e_steps is set in the main routine;
// Timer 0 is shared with millies
ISR(TIMER0_COMPA_vect) { Stepper::advance_isr(); }
void Stepper::advance_isr() {
old_OCR0A += eISR_Rate;
OCR0A = old_OCR0A;
#define SET_E_STEP_DIR(INDEX) \
if (e_steps[INDEX]) E## INDEX ##_DIR_WRITE(e_steps[INDEX] < 0 ? INVERT_E## INDEX ##_DIR : !INVERT_E## INDEX ##_DIR)
#define START_E_PULSE(INDEX) \
if (e_steps[INDEX]) E## INDEX ##_STEP_WRITE(!INVERT_E_STEP_PIN)
#define STOP_E_PULSE(INDEX) \
if (e_steps[INDEX]) { \
e_steps[INDEX] < 0 ? ++e_steps[INDEX] : --e_steps[INDEX]; \
E## INDEX ##_STEP_WRITE(INVERT_E_STEP_PIN); \
}
SET_E_STEP_DIR(0);
#if E_STEPPERS > 1
SET_E_STEP_DIR(1);
#if E_STEPPERS > 2
SET_E_STEP_DIR(2);
#if E_STEPPERS > 3
SET_E_STEP_DIR(3);
#endif
#endif
#endif
#define CYCLES_EATEN_BY_E 60
// Step all E steppers that have steps
for (uint8_t i = 0; i < step_loops; i++) {
#if STEP_PULSE_CYCLES > CYCLES_EATEN_BY_E
static uint32_t pulse_start;
pulse_start = TCNT0;
#endif
START_E_PULSE(0);
#if E_STEPPERS > 1
START_E_PULSE(1);
#if E_STEPPERS > 2
START_E_PULSE(2);
#if E_STEPPERS > 3
START_E_PULSE(3);
#endif
#endif
#endif
// For a minimum pulse time wait before stopping pulses
#if STEP_PULSE_CYCLES > CYCLES_EATEN_BY_E
while ((uint32_t)(TCNT0 - pulse_start) < STEP_PULSE_CYCLES - CYCLES_EATEN_BY_E) { /* nada */ }
#endif
STOP_E_PULSE(0);
#if E_STEPPERS > 1
STOP_E_PULSE(1);
#if E_STEPPERS > 2
STOP_E_PULSE(2);
#if E_STEPPERS > 3
STOP_E_PULSE(3);
#endif
#endif
#endif
}
}
#endif // ADVANCE or LIN_ADVANCE
void Stepper::init() {
// Init Digipot Motor Current
#if HAS_DIGIPOTSS || HAS_MOTOR_CURRENT_PWM
digipot_init();
#endif
// Init Microstepping Pins
#if HAS_MICROSTEPS
microstep_init();
#endif
// Init TMC Steppers
#if ENABLED(HAVE_TMCDRIVER)
tmc_init();
#endif
// Init L6470 Steppers
#if ENABLED(HAVE_L6470DRIVER)
L6470_init();
#endif
// Init Dir Pins
#if HAS_X_DIR
X_DIR_INIT;
#endif
#if HAS_X2_DIR
X2_DIR_INIT;
#endif
#if HAS_Y_DIR
Y_DIR_INIT;
#if ENABLED(Y_DUAL_STEPPER_DRIVERS) && HAS_Y2_DIR
Y2_DIR_INIT;
#endif
#endif
#if HAS_Z_DIR
Z_DIR_INIT;
#if ENABLED(Z_DUAL_STEPPER_DRIVERS) && HAS_Z2_DIR
Z2_DIR_INIT;
#endif
#endif
#if HAS_E0_DIR
E0_DIR_INIT;
#endif
#if HAS_E1_DIR
E1_DIR_INIT;
#endif
#if HAS_E2_DIR
E2_DIR_INIT;
#endif
#if HAS_E3_DIR
E3_DIR_INIT;
#endif
// Init Enable Pins - steppers default to disabled.
#if HAS_X_ENABLE
X_ENABLE_INIT;
if (!X_ENABLE_ON) X_ENABLE_WRITE(HIGH);
#if ENABLED(DUAL_X_CARRIAGE) && HAS_X2_ENABLE
X2_ENABLE_INIT;
if (!X_ENABLE_ON) X2_ENABLE_WRITE(HIGH);
#endif
#endif
#if HAS_Y_ENABLE
Y_ENABLE_INIT;
if (!Y_ENABLE_ON) Y_ENABLE_WRITE(HIGH);
#if ENABLED(Y_DUAL_STEPPER_DRIVERS) && HAS_Y2_ENABLE
Y2_ENABLE_INIT;
if (!Y_ENABLE_ON) Y2_ENABLE_WRITE(HIGH);
#endif
#endif
#if HAS_Z_ENABLE
Z_ENABLE_INIT;
if (!Z_ENABLE_ON) Z_ENABLE_WRITE(HIGH);
#if ENABLED(Z_DUAL_STEPPER_DRIVERS) && HAS_Z2_ENABLE
Z2_ENABLE_INIT;
if (!Z_ENABLE_ON) Z2_ENABLE_WRITE(HIGH);
#endif
#endif
#if HAS_E0_ENABLE
E0_ENABLE_INIT;
if (!E_ENABLE_ON) E0_ENABLE_WRITE(HIGH);
#endif
#if HAS_E1_ENABLE
E1_ENABLE_INIT;
if (!E_ENABLE_ON) E1_ENABLE_WRITE(HIGH);
#endif
#if HAS_E2_ENABLE
E2_ENABLE_INIT;
if (!E_ENABLE_ON) E2_ENABLE_WRITE(HIGH);
#endif
#if HAS_E3_ENABLE
E3_ENABLE_INIT;
if (!E_ENABLE_ON) E3_ENABLE_WRITE(HIGH);
#endif
// Init endstops and pullups
endstops.init();
#define _STEP_INIT(AXIS) AXIS ##_STEP_INIT
#define _WRITE_STEP(AXIS, HIGHLOW) AXIS ##_STEP_WRITE(HIGHLOW)
#define _DISABLE(axis) disable_## axis()
#define AXIS_INIT(axis, AXIS, PIN) \
_STEP_INIT(AXIS); \
_WRITE_STEP(AXIS, _INVERT_STEP_PIN(PIN)); \
_DISABLE(axis)
#define E_AXIS_INIT(NUM) AXIS_INIT(e## NUM, E## NUM, E)
// Init Step Pins
#if HAS_X_STEP
#if ENABLED(X_DUAL_STEPPER_DRIVERS) || ENABLED(DUAL_X_CARRIAGE)
X2_STEP_INIT;
X2_STEP_WRITE(INVERT_X_STEP_PIN);
#endif
AXIS_INIT(x, X, X);
#endif
#if HAS_Y_STEP
#if ENABLED(Y_DUAL_STEPPER_DRIVERS)
Y2_STEP_INIT;
Y2_STEP_WRITE(INVERT_Y_STEP_PIN);
#endif
AXIS_INIT(y, Y, Y);
#endif
#if HAS_Z_STEP
#if ENABLED(Z_DUAL_STEPPER_DRIVERS)
Z2_STEP_INIT;
Z2_STEP_WRITE(INVERT_Z_STEP_PIN);
#endif
AXIS_INIT(z, Z, Z);
#endif
#if HAS_E0_STEP
E_AXIS_INIT(0);
#endif
#if HAS_E1_STEP
E_AXIS_INIT(1);
#endif
#if HAS_E2_STEP
E_AXIS_INIT(2);
#endif
#if HAS_E3_STEP
E_AXIS_INIT(3);
#endif
// waveform generation = 0100 = CTC
CBI(TCCR1B, WGM13);
SBI(TCCR1B, WGM12);
CBI(TCCR1A, WGM11);
CBI(TCCR1A, WGM10);
// output mode = 00 (disconnected)
TCCR1A &= ~(3 << COM1A0);
TCCR1A &= ~(3 << COM1B0);
// Set the timer pre-scaler
// Generally we use a divider of 8, resulting in a 2MHz timer
// frequency on a 16MHz MCU. If you are going to change this, be
// sure to regenerate speed_lookuptable.h with
// create_speed_lookuptable.py
TCCR1B = (TCCR1B & ~(0x07 << CS10)) | (2 << CS10);
// Init Stepper ISR to 122 Hz for quick starting
OCR1A = 0x4000;
TCNT1 = 0;
ENABLE_STEPPER_DRIVER_INTERRUPT();
#if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
for (int i = 0; i < E_STEPPERS; i++) {
e_steps[i] = 0;
#if ENABLED(LIN_ADVANCE)
current_adv_steps[i] = 0;
#endif
}
#if defined(TCCR0A) && defined(WGM01)
CBI(TCCR0A, WGM01);
CBI(TCCR0A, WGM00);
#endif
SBI(TIMSK0, OCIE0A);
#endif // ADVANCE or LIN_ADVANCE
endstops.enable(true); // Start with endstops active. After homing they can be disabled
sei();
set_directions(); // Init directions to last_direction_bits = 0
}
/**
* Block until all buffered steps are executed
*/
void Stepper::synchronize() { while (planner.blocks_queued()) idle(); }
/**
* Set the stepper positions directly in steps
*
* The input is based on the typical per-axis XYZ steps.
* For CORE machines XYZ needs to be translated to ABC.
*
* This allows get_axis_position_mm to correctly
* derive the current XYZ position later on.
*/
void Stepper::set_position(const long &a, const long &b, const long &c, const long &e) {
synchronize(); // Bad to set stepper counts in the middle of a move
CRITICAL_SECTION_START;
#if ENABLED(COREXY)
// corexy positioning
// these equations follow the form of the dA and dB equations on http://www.corexy.com/theory.html
count_position[A_AXIS] = a + b;
count_position[B_AXIS] = a - b;
count_position[Z_AXIS] = c;
#elif ENABLED(COREXZ)
// corexz planning
count_position[A_AXIS] = a + c;
count_position[Y_AXIS] = b;
count_position[C_AXIS] = a - c;
#elif ENABLED(COREYZ)
// coreyz planning
count_position[X_AXIS] = a;
count_position[B_AXIS] = y + c;
count_position[C_AXIS] = y - c;
#else
// default non-h-bot planning
count_position[X_AXIS] = a;
count_position[Y_AXIS] = b;
count_position[Z_AXIS] = c;
#endif
count_position[E_AXIS] = e;
CRITICAL_SECTION_END;
}
void Stepper::set_position(const AxisEnum &axis, const long &v) {
CRITICAL_SECTION_START;
count_position[axis] = v;
CRITICAL_SECTION_END;
}
void Stepper::set_e_position(const long &e) {
CRITICAL_SECTION_START;
count_position[E_AXIS] = e;
CRITICAL_SECTION_END;
}
/**
* Get a stepper's position in steps.
*/
long Stepper::position(AxisEnum axis) {
CRITICAL_SECTION_START;
long count_pos = count_position[axis];
CRITICAL_SECTION_END;
return count_pos;
}
/**
* Get an axis position according to stepper position(s)
* For CORE machines apply translation from ABC to XYZ.
*/
float Stepper::get_axis_position_mm(AxisEnum axis) {
float axis_steps;
#if ENABLED(COREXY) || ENABLED(COREXZ) || ENABLED(COREYZ)
// Requesting one of the "core" axes?
if (axis == CORE_AXIS_1 || axis == CORE_AXIS_2) {
CRITICAL_SECTION_START;
long pos1 = count_position[CORE_AXIS_1],
pos2 = count_position[CORE_AXIS_2];
CRITICAL_SECTION_END;
// ((a1+a2)+(a1-a2))/2 -> (a1+a2+a1-a2)/2 -> (a1+a1)/2 -> a1
// ((a1+a2)-(a1-a2))/2 -> (a1+a2-a1+a2)/2 -> (a2+a2)/2 -> a2
axis_steps = (pos1 + ((axis == CORE_AXIS_1) ? pos2 : -pos2)) * 0.5f;
}
else
axis_steps = position(axis);
#else
axis_steps = position(axis);
#endif
return axis_steps * planner.steps_to_mm[axis];
}
void Stepper::finish_and_disable() {
synchronize();
disable_all_steppers();
}
void Stepper::quick_stop() {
cleaning_buffer_counter = 5000;
DISABLE_STEPPER_DRIVER_INTERRUPT();
while (planner.blocks_queued()) planner.discard_current_block();
current_block = NULL;
ENABLE_STEPPER_DRIVER_INTERRUPT();
}
void Stepper::endstop_triggered(AxisEnum axis) {
#if ENABLED(COREXY) || ENABLED(COREXZ) || ENABLED(COREYZ)
float axis_pos = count_position[axis];
if (axis == CORE_AXIS_1)
axis_pos = (axis_pos + count_position[CORE_AXIS_2]) * 0.5;
else if (axis == CORE_AXIS_2)
axis_pos = (count_position[CORE_AXIS_1] - axis_pos) * 0.5;
endstops_trigsteps[axis] = axis_pos;
#else // !COREXY && !COREXZ && !COREYZ
endstops_trigsteps[axis] = count_position[axis];
#endif // !COREXY && !COREXZ && !COREYZ
kill_current_block();
}
void Stepper::report_positions() {
CRITICAL_SECTION_START;
long xpos = count_position[X_AXIS],
ypos = count_position[Y_AXIS],
zpos = count_position[Z_AXIS];
CRITICAL_SECTION_END;
#if ENABLED(COREXY) || ENABLED(COREXZ) || IS_SCARA
SERIAL_PROTOCOLPGM(MSG_COUNT_A);
#else
SERIAL_PROTOCOLPGM(MSG_COUNT_X);
#endif
SERIAL_PROTOCOL(xpos);
#if ENABLED(COREXY) || ENABLED(COREYZ) || IS_SCARA
SERIAL_PROTOCOLPGM(" B:");
#else
SERIAL_PROTOCOLPGM(" Y:");
#endif
SERIAL_PROTOCOL(ypos);
#if ENABLED(COREXZ) || ENABLED(COREYZ)
SERIAL_PROTOCOLPGM(" C:");
#else
SERIAL_PROTOCOLPGM(" Z:");
#endif
SERIAL_PROTOCOL(zpos);
SERIAL_EOL;
}
#if ENABLED(BABYSTEPPING)
// MUST ONLY BE CALLED BY AN ISR,
// No other ISR should ever interrupt this!
void Stepper::babystep(const uint8_t axis, const bool direction) {
#define _ENABLE(axis) enable_## axis()
#define _READ_DIR(AXIS) AXIS ##_DIR_READ
#define _INVERT_DIR(AXIS) INVERT_## AXIS ##_DIR
#define _APPLY_DIR(AXIS, INVERT) AXIS ##_APPLY_DIR(INVERT, true)
#define BABYSTEP_AXIS(axis, AXIS, INVERT) { \
_ENABLE(axis); \
uint8_t old_pin = _READ_DIR(AXIS); \
_APPLY_DIR(AXIS, _INVERT_DIR(AXIS)^direction^INVERT); \
_APPLY_STEP(AXIS)(!_INVERT_STEP_PIN(AXIS), true); \
delayMicroseconds(2); \
_APPLY_STEP(AXIS)(_INVERT_STEP_PIN(AXIS), true); \
_APPLY_DIR(AXIS, old_pin); \
}
switch (axis) {
case X_AXIS:
BABYSTEP_AXIS(x, X, false);
break;
case Y_AXIS:
BABYSTEP_AXIS(y, Y, false);
break;
case Z_AXIS: {
#if DISABLED(DELTA)
BABYSTEP_AXIS(z, Z, BABYSTEP_INVERT_Z);
#else // DELTA
bool z_direction = direction ^ BABYSTEP_INVERT_Z;
enable_x();
enable_y();
enable_z();
uint8_t old_x_dir_pin = X_DIR_READ,
old_y_dir_pin = Y_DIR_READ,
old_z_dir_pin = Z_DIR_READ;
//setup new step
X_DIR_WRITE(INVERT_X_DIR ^ z_direction);
Y_DIR_WRITE(INVERT_Y_DIR ^ z_direction);
Z_DIR_WRITE(INVERT_Z_DIR ^ z_direction);
//perform step
X_STEP_WRITE(!INVERT_X_STEP_PIN);
Y_STEP_WRITE(!INVERT_Y_STEP_PIN);
Z_STEP_WRITE(!INVERT_Z_STEP_PIN);
delayMicroseconds(2);
X_STEP_WRITE(INVERT_X_STEP_PIN);
Y_STEP_WRITE(INVERT_Y_STEP_PIN);
Z_STEP_WRITE(INVERT_Z_STEP_PIN);
//get old pin state back.
X_DIR_WRITE(old_x_dir_pin);
Y_DIR_WRITE(old_y_dir_pin);
Z_DIR_WRITE(old_z_dir_pin);
#endif
} break;
default: break;
}
}
#endif //BABYSTEPPING
/**
* Software-controlled Stepper Motor Current
*/
#if HAS_DIGIPOTSS
// From Arduino DigitalPotControl example
void Stepper::digitalPotWrite(int address, int value) {
WRITE(DIGIPOTSS_PIN, LOW); // take the SS pin low to select the chip
SPI.transfer(address); // send in the address and value via SPI:
SPI.transfer(value);
WRITE(DIGIPOTSS_PIN, HIGH); // take the SS pin high to de-select the chip:
//delay(10);
}
#endif //HAS_DIGIPOTSS
#if HAS_DIGIPOTSS || HAS_MOTOR_CURRENT_PWM
void Stepper::digipot_init() {
#if HAS_DIGIPOTSS
static const uint8_t digipot_motor_current[] = DIGIPOT_MOTOR_CURRENT;
SPI.begin();
SET_OUTPUT(DIGIPOTSS_PIN);
for (uint8_t i = 0; i < COUNT(digipot_motor_current); i++) {
//digitalPotWrite(digipot_ch[i], digipot_motor_current[i]);
digipot_current(i, digipot_motor_current[i]);
}
#elif HAS_MOTOR_CURRENT_PWM
#if PIN_EXISTS(MOTOR_CURRENT_PWM_XY)
SET_OUTPUT(MOTOR_CURRENT_PWM_XY_PIN);
digipot_current(0, motor_current_setting[0]);
#endif
#if PIN_EXISTS(MOTOR_CURRENT_PWM_Z)
SET_OUTPUT(MOTOR_CURRENT_PWM_Z_PIN);
digipot_current(1, motor_current_setting[1]);
#endif
#if PIN_EXISTS(MOTOR_CURRENT_PWM_E)
SET_OUTPUT(MOTOR_CURRENT_PWM_E_PIN);
digipot_current(2, motor_current_setting[2]);
#endif
//Set timer5 to 31khz so the PWM of the motor power is as constant as possible. (removes a buzzing noise)
TCCR5B = (TCCR5B & ~(_BV(CS50) | _BV(CS51) | _BV(CS52))) | _BV(CS50);
#endif
}
void Stepper::digipot_current(uint8_t driver, int current) {
#if HAS_DIGIPOTSS
const uint8_t digipot_ch[] = DIGIPOT_CHANNELS;
digitalPotWrite(digipot_ch[driver], current);
#elif HAS_MOTOR_CURRENT_PWM
#define _WRITE_CURRENT_PWM(P) analogWrite(P, 255L * current / (MOTOR_CURRENT_PWM_RANGE))
switch (driver) {
#if PIN_EXISTS(MOTOR_CURRENT_PWM_XY)
case 0: _WRITE_CURRENT_PWM(MOTOR_CURRENT_PWM_XY_PIN); break;
#endif
#if PIN_EXISTS(MOTOR_CURRENT_PWM_Z)
case 1: _WRITE_CURRENT_PWM(MOTOR_CURRENT_PWM_Z_PIN); break;
#endif
#if PIN_EXISTS(MOTOR_CURRENT_PWM_E)
case 2: _WRITE_CURRENT_PWM(MOTOR_CURRENT_PWM_E_PIN); break;
#endif
}
#endif
}
#endif
#if HAS_MICROSTEPS
/**
* Software-controlled Microstepping
*/
void Stepper::microstep_init() {
SET_OUTPUT(X_MS1_PIN);
SET_OUTPUT(X_MS2_PIN);
#if HAS_MICROSTEPS_Y
SET_OUTPUT(Y_MS1_PIN);
SET_OUTPUT(Y_MS2_PIN);
#endif
#if HAS_MICROSTEPS_Z
SET_OUTPUT(Z_MS1_PIN);
SET_OUTPUT(Z_MS2_PIN);
#endif
#if HAS_MICROSTEPS_E0
SET_OUTPUT(E0_MS1_PIN);
SET_OUTPUT(E0_MS2_PIN);
#endif
#if HAS_MICROSTEPS_E1
SET_OUTPUT(E1_MS1_PIN);
SET_OUTPUT(E1_MS2_PIN);
#endif
static const uint8_t microstep_modes[] = MICROSTEP_MODES;
for (uint16_t i = 0; i < COUNT(microstep_modes); i++)
microstep_mode(i, microstep_modes[i]);
}
void Stepper::microstep_ms(uint8_t driver, int8_t ms1, int8_t ms2) {
if (ms1 >= 0) switch (driver) {
case 0: digitalWrite(X_MS1_PIN, ms1); break;
#if HAS_MICROSTEPS_Y
case 1: digitalWrite(Y_MS1_PIN, ms1); break;
#endif
#if HAS_MICROSTEPS_Z
case 2: digitalWrite(Z_MS1_PIN, ms1); break;
#endif
#if HAS_MICROSTEPS_E0
case 3: digitalWrite(E0_MS1_PIN, ms1); break;
#endif
#if HAS_MICROSTEPS_E1
case 4: digitalWrite(E1_MS1_PIN, ms1); break;
#endif
}
if (ms2 >= 0) switch (driver) {
case 0: digitalWrite(X_MS2_PIN, ms2); break;
#if HAS_MICROSTEPS_Y
case 1: digitalWrite(Y_MS2_PIN, ms2); break;
#endif
#if HAS_MICROSTEPS_Z
case 2: digitalWrite(Z_MS2_PIN, ms2); break;
#endif
#if HAS_MICROSTEPS_E0
case 3: digitalWrite(E0_MS2_PIN, ms2); break;
#endif
#if HAS_MICROSTEPS_E1
case 4: digitalWrite(E1_MS2_PIN, ms2); break;
#endif
}
}
void Stepper::microstep_mode(uint8_t driver, uint8_t stepping_mode) {
switch (stepping_mode) {
case 1: microstep_ms(driver, MICROSTEP1); break;
case 2: microstep_ms(driver, MICROSTEP2); break;
case 4: microstep_ms(driver, MICROSTEP4); break;
case 8: microstep_ms(driver, MICROSTEP8); break;
case 16: microstep_ms(driver, MICROSTEP16); break;
}
}
void Stepper::microstep_readings() {
SERIAL_PROTOCOLLNPGM("MS1,MS2 Pins");
SERIAL_PROTOCOLPGM("X: ");
SERIAL_PROTOCOL(READ(X_MS1_PIN));
SERIAL_PROTOCOLLN(READ(X_MS2_PIN));
#if HAS_MICROSTEPS_Y
SERIAL_PROTOCOLPGM("Y: ");
SERIAL_PROTOCOL(READ(Y_MS1_PIN));
SERIAL_PROTOCOLLN(READ(Y_MS2_PIN));
#endif
#if HAS_MICROSTEPS_Z
SERIAL_PROTOCOLPGM("Z: ");
SERIAL_PROTOCOL(READ(Z_MS1_PIN));
SERIAL_PROTOCOLLN(READ(Z_MS2_PIN));
#endif
#if HAS_MICROSTEPS_E0
SERIAL_PROTOCOLPGM("E0: ");
SERIAL_PROTOCOL(READ(E0_MS1_PIN));
SERIAL_PROTOCOLLN(READ(E0_MS2_PIN));
#endif
#if HAS_MICROSTEPS_E1
SERIAL_PROTOCOLPGM("E1: ");
SERIAL_PROTOCOL(READ(E1_MS1_PIN));
SERIAL_PROTOCOLLN(READ(E1_MS2_PIN));
#endif
}
#endif // HAS_MICROSTEPS
#if ENABLED(LIN_ADVANCE)
void Stepper::advance_M905(const float &k) {
if (k >= 0) extruder_advance_k = k;
SERIAL_ECHO_START;
SERIAL_ECHOPAIR("Advance factor: ", extruder_advance_k);
SERIAL_EOL;
}
#endif // LIN_ADVANCE