Without this fix, the code wont compile with extruder but without bed
runaway protection defined.

* Adds config parameter `PID_PARAMS_PER_EXTRUDER` - allows single PID
parameters to be used where this would be preferable (e.g. dual
identical extruders)
* When disabled, will use `float Kp, Ki, Kd, Kc;` as before.
Preprocessor macros used to switch between.
* ultralcd.cpp defines extra menus for extra parameters only where
required
* M301 reports `e:xx` only if independent pid parameters enabled
* EEPROM structure still leaves space for 3 extruders worth, when undef
will save single parameter to all extruder positions, but only read the
first
* Switching off saves approx 330 B with no LCD enabled, 2634B with LCD
(RRD) enabled: this is significant.
* LCD modifications should be tested.

* Variables Kp, Ki, Kd, Kc now arrays of size EXTRUDERS
* M301 gains (optional, default=0) E parameter to define which
extruder's settings to modify. Tested, works with Repetier Host's EEPROM
config window, albeit only reads/updates settings for E0.
* All Kp, Ki, Kd, Kc parameters saved in EEPROM (version now v14), up to
3 extruders supported (same as Marlin in general)

There is the possibility of turn on this features adding "#define SLOW_PWM_HEATERS" in Configuration.h

Added boards.h which contains defines for all the board numbers, plus
some shorthand macros for less typing.

Added boards.h which contains defines for all the board numbers, plus
some shorthand macros for less typing.

Improvement to avoid reinitializing delay buffer with every print. Fixed
issues in buffer indexing and memory out of bounds due to floating point
imprecision.  Simplified the code by avoiding conversion to standard
diameter and 1cu mm extrusion, which caused complications in determining
mm extruded.

This feature allows the printer to read the filament diameter
automatically and adjust the printer in real time.  Added code to read
an analog voltage that represents a filament diameter measurement.  This
measurement is delayed in a ring buffer to compensate for sensors that
are a distance away from the extruder.  The measurement is used to
adjust the volumetric_multiplier for the extruder.  Some additional g
codes (M404, M405, M406, M407) are used to set parameters and turn
on/off the control. g code M221 is updated.  Pins for RAMPS1.4, RAMBO,
and Printrboard are identified for analog input.  The configuration file
is updated with relevant user parameters.

This is a feature to protect your printer from burn up in flames if it
has a thermistor coming off place (this happened to a friend of mine
recently and motivated me writing this feature).

The issue: If a thermistor come off, it will read a lower temperature
than actual. The system will turn the heater on forever, burning up the
filament and anything
else around.

After the temperature reaches the target for the first time, this
feature will start measuring for how long the current temperature stays
below the target minus _HYSTERESIS (set_temperature -
THERMAL_RUNAWAY_PROTECTION_HYSTERESIS).

If it stays longer than _PERIOD, it means the thermistor temperature
cannot catch up with the target, so something *may be* wrong. Then, to
be on the safe side, the system will he halt.

Bear in mind the count down will just start AFTER the first time the
thermistor temperature is over the target, so you will have no problem
if your extruder heater takes 2 minutes to hit the target on heating.

Enables both SD card and MAX6675 to talk with each other
Fixes also issue #750

This is a feature to protect your printer from burn up in flames if it
has a thermistor coming off place (this happened to a friend of mine
recently and motivated me writing this feature).

The issue: If a thermistor come off, it will read a lower temperature
than actual. The system will turn the heater on forever, burning up the
filament and anything
else around.

After the temperature reaches the target for the first time, this
feature will start measuring for how long the current temperature stays
below the target minus _HYSTERESIS (set_temperature -
THERMAL_RUNAWAY_PROTECTION_HYSTERESIS).

If it stays longer than _PERIOD, it means the thermistor temperature
cannot catch up with the target, so something *may be* wrong. Then, to
be on the safe side, the system will he halt.

Bear in mind the count down will just start AFTER the first time the
thermistor temperature is over the target, so you will have no problem
if your extruder heater takes 2 minutes to hit the target on heating.

===================================================
Hi,

Please find the latest report on new defect(s) introduced to ErikZalm/Marlin found with Coverity Scan.

Defect(s) Reported-by: Coverity Scan
Showing 15 of 15 defect(s)

** CID 59629:  Unchecked return value  (CHECKED_RETURN)
/Marlin_main.cpp: 2154 in process_commands()()

** CID 59630:  Operands don't affect result  (CONSTANT_EXPRESSION_RESULT)
/Applications/Arduino.app/Contents/Resources/Java/hardware/arduino/cores/arduino/Tone.cpp: 319 in tone(unsigned char, unsigned int, unsigned long)()

** CID 59631:  Missing break in switch  (MISSING_BREAK)
/Marlin_main.cpp: 1187 in process_commands()()

** CID 59632:  Missing break in switch  (MISSING_BREAK)
/Marlin_main.cpp: 1193 in process_commands()()

** CID 59633:  Out-of-bounds write  (OVERRUN)
/temperature.cpp: 914 in disable_heater()()

** CID 59634:  Out-of-bounds write  (OVERRUN)
/temperature.cpp: 913 in disable_heater()()

** CID 59635:  Out-of-bounds read  (OVERRUN)
/temperature.cpp: 626 in analog2temp(int, unsigned char)()

** CID 59636:  Out-of-bounds read  (OVERRUN)
/temperature.cpp: 620 in analog2temp(int, unsigned char)()

** CID 59637:  Out-of-bounds write  (OVERRUN)
/temperature.cpp: 202 in PID_autotune(float, int, int)()

** CID 59638:  Out-of-bounds read  (OVERRUN)
/temperature.cpp: 214 in PID_autotune(float, int, int)()

** CID 59639:  Out-of-bounds write  (OVERRUN)
/Marlin_main.cpp: 2278 in process_commands()()

** CID 59640:  Out-of-bounds read  (OVERRUN)
/Marlin_main.cpp: 1802 in process_commands()()

** CID 59641:  Uninitialized scalar field  (UNINIT_CTOR)
/Applications/Arduino.app/Contents/Resources/Java/libraries/LiquidCrystal/LiquidCrystal.cpp: 51 in LiquidCrystal::LiquidCrystal(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)()

** CID 59642:  Uninitialized scalar field  (UNINIT_CTOR)
/Applications/Arduino.app/Contents/Resources/Java/libraries/LiquidCrystal/LiquidCrystal.cpp: 45 in LiquidCrystal::LiquidCrystal(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)()

** CID 59643:  Uninitialized scalar field  (UNINIT_CTOR)
/Applications/Arduino.app/Contents/Resources/Java/libraries/LiquidCrystal/LiquidCrystal.cpp: 32 in LiquidCrystal::LiquidCrystal(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)()

________________________________________________________________________________________________________
*** CID 59629:  Unchecked return value  (CHECKED_RETURN)
/Marlin_main.cpp: 2154 in process_commands()()
2148                 }
2149               #endif
2150             }
2151           }
2152           break;
2153         case 85: // M85
   CID 59629:  Unchecked return value  (CHECKED_RETURN)
   Calling "code_seen" without checking return value (as is done elsewhere 66 out of 67 times).
2154           code_seen('S');
2155           max_inactive_time = code_value() * 1000;
2156           break;
2157         case 92: // M92
2158           for(int8_t i=0; i < NUM_AXIS; i++)
2159           {

________________________________________________________________________________________________________
*** CID 59630:  Operands don't affect result  (CONSTANT_EXPRESSION_RESULT)
/Applications/Arduino.app/Contents/Resources/Java/hardware/arduino/cores/arduino/Tone.cpp: 319 in tone(unsigned char, unsigned int, unsigned long)()
313         else
314         {
315           // two choices for the 16 bit timers: ck/1 or ck/64
316           ocr = F_CPU / frequency / 2 - 1;
317
318           prescalarbits = 0b001;
   CID 59630:  Operands don't affect result  (CONSTANT_EXPRESSION_RESULT)
   "ocr > 65535U" is always false regardless of the values of its operands. This occurs as the logical operand of if.
319           if (ocr > 0xffff)
320           {
321             ocr = F_CPU / frequency / 2 / 64 - 1;
322             prescalarbits = 0b011;
323           }
324

________________________________________________________________________________________________________
*** CID 59631:  Missing break in switch  (MISSING_BREAK)
/Marlin_main.cpp: 1187 in process_commands()()
1181         case 2: // G2  - CW ARC
1182           if(Stopped == false) {
1183             get_arc_coordinates();
1184             prepare_arc_move(true);
1185             return;
1186           }
   CID 59631:  Missing break in switch  (MISSING_BREAK)
   The above case falls through to this one.
1187         case 3: // G3  - CCW ARC
1188           if(Stopped == false) {
1189             get_arc_coordinates();
1190             prepare_arc_move(false);
1191             return;
1192           }

________________________________________________________________________________________________________
*** CID 59632:  Missing break in switch  (MISSING_BREAK)
/Marlin_main.cpp: 1193 in process_commands()()
1187         case 3: // G3  - CCW ARC
1188           if(Stopped == false) {
1189             get_arc_coordinates();
1190             prepare_arc_move(false);
1191             return;
1192           }
   CID 59632:  Missing break in switch  (MISSING_BREAK)
   The above case falls through to this one.
1193         case 4: // G4 dwell
1194           LCD_MESSAGEPGM(MSG_DWELL);
1195           codenum = 0;
1196           if(code_seen('P')) codenum = code_value(); // milliseconds to wait
1197           if(code_seen('S')) codenum = code_value() * 1000; // seconds to wait
1198

________________________________________________________________________________________________________
*** CID 59633:  Out-of-bounds write  (OVERRUN)
/temperature.cpp: 914 in disable_heater()()
908          WRITE(HEATER_0_PIN,LOW);
909        #endif
910       #endif
911
912       #if defined(TEMP_1_PIN) && TEMP_1_PIN > -1
913         target_temperature[1]=0;
   CID 59633:  Out-of-bounds write  (OVERRUN)
   Overrunning array "soft_pwm" of 1 bytes at byte offset 1 using index "1".
914         soft_pwm[1]=0;
915         #if defined(HEATER_1_PIN) && HEATER_1_PIN > -1
916           WRITE(HEATER_1_PIN,LOW);
917         #endif
918       #endif
919

________________________________________________________________________________________________________
*** CID 59634:  Out-of-bounds write  (OVERRUN)
/temperature.cpp: 913 in disable_heater()()
907        #if defined(HEATER_0_PIN) && HEATER_0_PIN > -1
908          WRITE(HEATER_0_PIN,LOW);
909        #endif
910       #endif
911
912       #if defined(TEMP_1_PIN) && TEMP_1_PIN > -1
   CID 59634:  Out-of-bounds write  (OVERRUN)
   Overrunning array "target_temperature" of 1 2-byte elements at element index 1 (byte offset 2) using index "1".
913         target_temperature[1]=0;
914         soft_pwm[1]=0;
915         #if defined(HEATER_1_PIN) && HEATER_1_PIN > -1
916           WRITE(HEATER_1_PIN,LOW);
917         #endif
918       #endif

________________________________________________________________________________________________________
*** CID 59635:  Out-of-bounds read  (OVERRUN)
/temperature.cpp: 626 in analog2temp(int, unsigned char)()
620       if(heater_ttbl_map[e] != NULL)
621       {
622         float celsius = 0;
623         uint8_t i;
624         short (*tt)[][2] = (short (*)[][2])(heater_ttbl_map[e]);
625
   CID 59635:  Out-of-bounds read  (OVERRUN)
   Overrunning array "heater_ttbllen_map" of 1 bytes at byte offset 1 using index "e" (which evaluates to 1).
626         for (i=1; i<heater_ttbllen_map[e]; i++)
627         {
628           if (PGM_RD_W((*tt)[i][0]) > raw)
629           {
630             celsius = PGM_RD_W((*tt)[i-1][1]) +
631               (raw - PGM_RD_W((*tt)[i-1][0])) *

________________________________________________________________________________________________________
*** CID 59636:  Out-of-bounds read  (OVERRUN)
/temperature.cpp: 620 in analog2temp(int, unsigned char)()
614         if (e == 0)
615         {
616           return 0.25 * raw;
617         }
618       #endif
619
   CID 59636:  Out-of-bounds read  (OVERRUN)
   Overrunning array "heater_ttbl_map" of 1 2-byte elements at element index 1 (byte offset 2) using index "e" (which evaluates to 1).
620       if(heater_ttbl_map[e] != NULL)
621       {
622         float celsius = 0;
623         uint8_t i;
624         short (*tt)[][2] = (short (*)[][2])(heater_ttbl_map[e]);
625

________________________________________________________________________________________________________
*** CID 59637:  Out-of-bounds write  (OVERRUN)
/temperature.cpp: 202 in PID_autotune(float, int, int)()
196       {
197          soft_pwm_bed = (MAX_BED_POWER)/2;
198          bias = d = (MAX_BED_POWER)/2;
199        }
200        else
201        {
   CID 59637:  Out-of-bounds write  (OVERRUN)
   Overrunning array "soft_pwm" of 1 bytes at byte offset 1 using index "extruder" (which evaluates to 1).
202          soft_pwm[extruder] = (PID_MAX)/2;
203          bias = d = (PID_MAX)/2;
204       }
205
206
207

________________________________________________________________________________________________________
*** CID 59638:  Out-of-bounds read  (OVERRUN)
/temperature.cpp: 214 in PID_autotune(float, int, int)()
208
209      for(;;) {
210
211         if(temp_meas_ready == true) { // temp sample ready
212           updateTemperaturesFromRawValues();
213
   CID 59638:  Out-of-bounds read  (OVERRUN)
   Overrunning array "current_temperature" of 1 4-byte elements at element index 1 (byte offset 4) using index "extruder" (which evaluates to 1).
214           input = (extruder<0)?current_temperature_bed:current_temperature[extruder];
215
216           max=max(max,input);
217           min=min(min,input);
218           if(heating == true && input > temp) {
219             if(millis() - t2 > 5000) {

________________________________________________________________________________________________________
*** CID 59639:  Out-of-bounds write  (OVERRUN)
/Marlin_main.cpp: 2278 in process_commands()()
2272               tmp_extruder = code_value();
2273               if(tmp_extruder >= EXTRUDERS) {
2274                 SERIAL_ECHO_START;
2275                 SERIAL_ECHO(MSG_M200_INVALID_EXTRUDER);
2276               }
2277             }
   CID 59639:  Out-of-bounds write  (OVERRUN)
   Overrunning array "volumetric_multiplier" of 1 4-byte elements at element index 1 (byte offset 4) using index "tmp_extruder" (which evaluates to 1).
2278             volumetric_multiplier[tmp_extruder] = 1 / area;
2279           }
2280           break;
2281         case 201: // M201
2282           for(int8_t i=0; i < NUM_AXIS; i++)
2283           {

________________________________________________________________________________________________________
*** CID 59640:  Out-of-bounds read  (OVERRUN)
/Marlin_main.cpp: 1802 in process_commands()()
1796             int pin_status = code_value();
1797             int pin_number = LED_PIN;
1798             if (code_seen('P') && pin_status >= 0 && pin_status <= 255)
1799               pin_number = code_value();
1800             for(int8_t i = 0; i < (int8_t)sizeof(sensitive_pins); i++)
1801             {
   CID 59640:  Out-of-bounds read  (OVERRUN)
   Overrunning array "sensitive_pins" of 28 2-byte elements at element index 55 (byte offset 110) using index "i" (which evaluates to 55).
1802               if (sensitive_pins[i] == pin_number)
1803               {
1804                 pin_number = -1;
1805                 break;
1806               }
1807             }

________________________________________________________________________________________________________
*** CID 59641:  Uninitialized scalar field  (UNINIT_CTOR)
/Applications/Arduino.app/Contents/Resources/Java/libraries/LiquidCrystal/LiquidCrystal.cpp: 51 in LiquidCrystal::LiquidCrystal(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)()
45     }
46
47     LiquidCrystal::LiquidCrystal(uint8_t rs,  uint8_t enable,
48     			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
49     {
50       init(1, rs, 255, enable, d0, d1, d2, d3, 0, 0, 0, 0);
   CID 59641:  Uninitialized scalar field  (UNINIT_CTOR)
   Non-static class member "_initialized" is not initialized in this constructor nor in any functions that it calls.
51     }
52
53     void LiquidCrystal::init(uint8_t fourbitmode, uint8_t rs, uint8_t rw, uint8_t enable,
54     			 uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
55     			 uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
56     {

________________________________________________________________________________________________________
*** CID 59642:  Uninitialized scalar field  (UNINIT_CTOR)
/Applications/Arduino.app/Contents/Resources/Java/libraries/LiquidCrystal/LiquidCrystal.cpp: 45 in LiquidCrystal::LiquidCrystal(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)()
39     }
40
41     LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
42     			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
43     {
44       init(1, rs, rw, enable, d0, d1, d2, d3, 0, 0, 0, 0);
   CID 59642:  Uninitialized scalar field  (UNINIT_CTOR)
   Non-static class member "_initialized" is not initialized in this constructor nor in any functions that it calls.
45     }
46
47     LiquidCrystal::LiquidCrystal(uint8_t rs,  uint8_t enable,
48     			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
49     {
50       init(1, rs, 255, enable, d0, d1, d2, d3, 0, 0, 0, 0);

________________________________________________________________________________________________________
*** CID 59643:  Uninitialized scalar field  (UNINIT_CTOR)
/Applications/Arduino.app/Contents/Resources/Java/libraries/LiquidCrystal/LiquidCrystal.cpp: 32 in LiquidCrystal::LiquidCrystal(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)()
26
27     LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
28     			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
29     			     uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
30     {
31       init(0, rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7);
   CID 59643:  Uninitialized scalar field  (UNINIT_CTOR)
   Non-static class member "_initialized" is not initialized in this constructor nor in any functions that it calls.
32     }
33
34     LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t enable,
35     			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
36     			     uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
37     {

________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, http://scan.coverity.com/projects/2224?tab=overview

Users can be confused as to which values to enter after a PID tune. Updating the message to help clarity it.
New message: "PID Autotune finished! Put the last Kp, Ki and Kd constants from above into Configuration.h"

Old message: "PID Autotune finished! Put the Kp, Ki and Kd constants into Configuration.h"

In some cases the Bed Heater FET heats up more then stepper drivers, so
this change add the bed monitoring to the controller fan. As soon as the
bed heater is turned on, the controller fan will run as well.

In previous version, even with PWM = 127, the system turns the FET off
and then on in the next cycle. This bevavior may increase the FET heat
dissipation.
It was fixed keeping the FET always On when PWM=127.

This allows a hot end with two heaters and a FET for each heater. This is useful if the FET is not capable of heating two heaters.

It is a realtime control over the head position via the LCD menu system that works _while_ printing.
Using it, one can e.g. tune the z-position in realtime, while printing the first layer.
Also, lost steps can be manually added/removed, but thats not the prime feature.
Stuff is placed into the Tune->Babystep *

It is not possible to have realtime control via gcode sending due to the buffering, so I did not include a gcode yet. However, it could be added, but it movements will not be realtime then.

Historically, a very similar thing was implemented for the "Kaamermaker" project, while Joris was babysitting his offspring, hence the name.

say goodby to fuddling around with the z-axis.

Diffed and merged, preserving my updates

Reviert previous change of #if BLAH_PIN > 0 to #if defined(BLAH_PIN) &&
BLAH_PIN > -1. Unfortunately some times pin 0 is used. For my sins I've
gone through and replaced all unsafe checks of #if BLAH_PIN > -1 with
the safe version.

Also cosmetic comment changes and spelling corrections in printed
messages