Marlin_main.cpp

/* -*- c++ -*- */

/*
    Reprap firmware 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/>.
 */

/*
 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"

#ifdef ENABLE_AUTO_BED_LEVELING
  #if Z_MIN_PIN == -1
    #error "You must have a Z_MIN endstop to enable Auto Bed Leveling feature. Z_MIN_PIN must point to a valid hardware pin."
  #endif
  #include "vector_3.h"
  #ifdef AUTO_BED_LEVELING_GRID
    #include "qr_solve.h"
  #endif
#endif // ENABLE_AUTO_BED_LEVELING

#define SERVO_LEVELING defined(ENABLE_AUTO_BED_LEVELING) && PROBE_SERVO_DEACTIVATION_DELAY > 0

#include "ultralcd.h"
#include "planner.h"
#include "stepper.h"
#include "temperature.h"
#include "motion_control.h"
#include "cardreader.h"
#include "watchdog.h"
#include "ConfigurationStore.h"
#include "language.h"
#include "pins_arduino.h"
#include "math.h"

#ifdef BLINKM
  #include "BlinkM.h"
  #include "Wire.h"
#endif

#if NUM_SERVOS > 0
  #include "Servo.h"
#endif

#if defined(DIGIPOTSS_PIN) && DIGIPOTSS_PIN > -1
  #include <SPI.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

//Implemented Codes
//-------------------
// G0  -> G1
// G1  - Coordinated Movement X Y Z E
// G2  - CW ARC
// G3  - CCW ARC
// G4  - Dwell S<seconds> or P<milliseconds>
// G10 - retract filament according to settings of M207
// G11 - retract recover filament according to settings of M208
// G28 - Home all Axis
// 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
// 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.
// 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 axis_steps_per_unit - same syntax as G92
// M104 - Set extruder target temp
// M105 - Read current temp
// M106 - Fan on
// M107 - Fan off
// 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
// M112 - Emergency stop
// M114 - Output current position to serial port
// M115 - Capabilities string
// M117 - display message
// 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
// 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.
// 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 D<millimeters>- set filament diameter and set E axis units to cubic millimeters (use S0 to set back to millimeters).
// 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 mm/sec
// M204 - Set default acceleration: S normal moves T filament only moves (M204 S3000 T7000) in mm/sec^2  also sets minimum segment time in ms (B20000) to prevent buffer under-runs and M20 minimum feedrate
// M205 -  advanced settings:  minimum travel speed S=while printing T=travel only,  B=minimum segment time X= maximum xy jerk, Z=maximum Z jerk, E=maximum E jerk
// M206 - Set additional homing offset
// M207 - Set retract length S[positive mm] F[feedrate mm/min] Z[additional zlift/hop], stays in mm regardless of M200 setting
// M208 - Set recover=unretract length S[positive mm surplus to the M207 S*] F[feedrate mm/sec]
// M209 - S<1=true/0=false> enable automatic retract detect if the slicer did not support G10/11: every normal extrude-only move will be classified as retract depending on the direction.
// M218 - Set hotend offset (in mm): T<extruder_number> X<offset_on_X> Y<offset_on_Y>
// M220 S<factor in percent>- set speed factor override percentage
// M221 S<factor in percent>- set extrude factor override percentage
// M226 P<pin number> S<pin state>- Wait until the specified pin reaches the state required
// 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 - N<dia in mm> Enter the nominal filament width (3mm, 1.75mm ) or will display nominal filament width without parameters
// M405 - Turn on Filament Sensor extrusion control.  Optional D<delay in cm> to set delay in centimeters between sensor and extruder 
// M406 - Turn off Filament Sensor extrusion control 
// M407 - Displays measured filament diameter 
// 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
// M666 - Set delta endstop adjustment
// M605 - Set dual x-carriage movement mode: S<mode> [ X<duplication x-offset> R<duplication temp offset> ]
// M907 - Set digital trimpot motor current using axis codes.
// M908 - Control digital trimpot directly.
// 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)
// M365 - SCARA calibration: Scaling factor, X, Y, Z axis
//************* SCARA End ***************

// M928 - Start SD logging (M928 filename.g) - ended by M29
// M999 - Restart after being stopped by error

#ifdef SDSUPPORT
  CardReader card;
#endif

float homing_feedrate[] = HOMING_FEEDRATE;
bool axis_relative_modes[] = AXIS_RELATIVE_MODES;
int feedmultiply = 100; //100->1 200->2
int saved_feedmultiply;
int extrudemultiply = 100; //100->1 200->2
int extruder_multiply[EXTRUDERS] = { 100
  #if EXTRUDERS > 1
    , 100
    #if EXTRUDERS > 2
      , 100
      #if EXTRUDERS > 3
        , 100
      #endif
    #endif
  #endif
};
bool volumetric_enabled = false;
float filament_size[EXTRUDERS] = { DEFAULT_NOMINAL_FILAMENT_DIA
  #if EXTRUDERS > 1
      , DEFAULT_NOMINAL_FILAMENT_DIA
    #if EXTRUDERS > 2
       , DEFAULT_NOMINAL_FILAMENT_DIA
      #if EXTRUDERS > 3
        , DEFAULT_NOMINAL_FILAMENT_DIA
      #endif
    #endif
  #endif
};
float volumetric_multiplier[EXTRUDERS] = {1.0
  #if EXTRUDERS > 1
    , 1.0
    #if EXTRUDERS > 2
      , 1.0
      #if EXTRUDERS > 3
        , 1.0
      #endif
    #endif
  #endif
};
float current_position[NUM_AXIS] = { 0.0, 0.0, 0.0, 0.0 };
float add_homing[3] = { 0, 0, 0 };
#ifdef DELTA
  float endstop_adj[3] = { 0, 0, 0 };
#endif

float min_pos[3] = { X_MIN_POS, Y_MIN_POS, Z_MIN_POS };
float max_pos[3] = { X_MAX_POS, Y_MAX_POS, Z_MAX_POS };
bool axis_known_position[3] = { false, false, false };
float zprobe_zoffset;

// Extruder offset
#if EXTRUDERS > 1
#ifndef DUAL_X_CARRIAGE
  #define NUM_EXTRUDER_OFFSETS 2 // only in XY plane
#else
  #define NUM_EXTRUDER_OFFSETS 3 // supports offsets in XYZ plane
#endif
float extruder_offset[NUM_EXTRUDER_OFFSETS][EXTRUDERS] = {
  #if defined(EXTRUDER_OFFSET_X)
    EXTRUDER_OFFSET_X
  #else
    0
  #endif
  ,
  #if defined(EXTRUDER_OFFSET_Y)
    EXTRUDER_OFFSET_Y
  #else
    0
  #endif
};
#endif

uint8_t active_extruder = 0;
int fanSpeed = 0;

#ifdef SERVO_ENDSTOPS
  int servo_endstops[] = SERVO_ENDSTOPS;
  int servo_endstop_angles[] = SERVO_ENDSTOP_ANGLES;
#endif

#ifdef BARICUDA
  int ValvePressure = 0;
  int EtoPPressure = 0;
#endif

#ifdef FWRETRACT

  bool autoretract_enabled = false;
  bool retracted[EXTRUDERS] = { false
    #if EXTRUDERS > 1
      , false
      #if EXTRUDERS > 2
        , false
        #if EXTRUDERS > 3
          , false
        #endif
      #endif
    #endif
  };
  bool retracted_swap[EXTRUDERS] = { false
    #if EXTRUDERS > 1
      , false
      #if EXTRUDERS > 2
        , false
        #if EXTRUDERS > 3
          , false
        #endif
      #endif
    #endif
  };

  float retract_length = RETRACT_LENGTH;
  float retract_length_swap = RETRACT_LENGTH_SWAP;
  float retract_feedrate = 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 = RETRACT_RECOVER_FEEDRATE;

#endif // FWRETRACT

#ifdef ULTIPANEL
  bool powersupply = 
    #ifdef PS_DEFAULT_OFF
      false
    #else
      true
    #endif
  ;
#endif

#ifdef DELTA
  float delta[3] = { 0, 0, 0 };
  #define SIN_60 0.8660254037844386
  #define COS_60 0.5
  // these are the default values, can be overriden with M665
  float delta_radius = DELTA_RADIUS;
  float delta_tower1_x = -SIN_60 * delta_radius; // front left tower
  float delta_tower1_y = -COS_60 * delta_radius;     
  float delta_tower2_x =  SIN_60 * delta_radius; // front right tower
  float delta_tower2_y = -COS_60 * delta_radius;     
  float delta_tower3_x = 0;                      // back middle tower
  float delta_tower3_y = delta_radius;
  float delta_diagonal_rod = DELTA_DIAGONAL_ROD;
  float delta_diagonal_rod_2 = sq(delta_diagonal_rod);
  float delta_segments_per_second = DELTA_SEGMENTS_PER_SECOND;
#endif

#ifdef SCARA
  float axis_scaling[3] = { 1, 1, 1 };    // Build size scaling, default to 1
#endif        

bool cancel_heatup = false;

#ifdef FILAMENT_SENSOR
  //Variables for Filament Sensor input 
  float filament_width_nominal=DEFAULT_NOMINAL_FILAMENT_DIA;  //Set nominal filament width, can be changed with M404 
  bool filament_sensor=false;  //M405 turns on filament_sensor control, M406 turns it off 
  float filament_width_meas=DEFAULT_MEASURED_FILAMENT_DIA; //Stores the measured filament diameter 
  signed char measurement_delay[MAX_MEASUREMENT_DELAY+1];  //ring buffer to delay measurement  store extruder factor after subtracting 100 
  int delay_index1=0;  //index into ring buffer
  int delay_index2=-1;  //index into ring buffer - set to -1 on startup to indicate ring buffer needs to be initialized
  float delay_dist=0; //delay distance counter  
  int meas_delay_cm = MEASUREMENT_DELAY_CM;  //distance delay setting
#endif

const char errormagic[] PROGMEM = "Error:";
const char echomagic[] PROGMEM = "echo:";

const char axis_codes[NUM_AXIS] = {'X', 'Y', 'Z', 'E'};
static float destination[NUM_AXIS] = { 0, 0, 0, 0 };

#ifndef DELTA
  static float delta[3] = { 0, 0, 0 };
#endif

static float offset[3] = { 0, 0, 0 };
static bool home_all_axis = true;
static float feedrate = 1500.0, next_feedrate, saved_feedrate;
static long gcode_N, gcode_LastN, Stopped_gcode_LastN = 0;

static bool relative_mode = false;  //Determines Absolute or Relative Coordinates

static char cmdbuffer[BUFSIZE][MAX_CMD_SIZE];
static bool fromsd[BUFSIZE];
static int bufindr = 0;
static int bufindw = 0;
static int buflen = 0;

static char serial_char;
static int serial_count = 0;
static boolean comment_mode = false;
static char *strchr_pointer; ///< A pointer to find chars in the command string (X, Y, Z, E, etc.)

const char* queued_commands_P= NULL; /* pointer to the current line in the active sequence of commands, or NULL when none */

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

// Inactivity shutdown
static unsigned long previous_millis_cmd = 0;
static unsigned long max_inactive_time = 0;
static unsigned long stepper_inactive_time = DEFAULT_STEPPER_DEACTIVE_TIME*1000l;

unsigned long starttime = 0; ///< Print job start time
unsigned long stoptime = 0;  ///< Print job stop time

static uint8_t tmp_extruder;


bool Stopped = false;

#if NUM_SERVOS > 0
  Servo servos[NUM_SERVOS];
#endif

bool CooldownNoWait = true;
bool target_direction;

#ifdef CHDK
  unsigned long chdkHigh = 0;
  boolean chdkActive = false;
#endif

//===========================================================================
//=============================Routines======================================
//===========================================================================

void get_arc_coordinates();
bool setTargetedHotend(int code);

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); }

#ifdef 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

//Injects the next command from the pending sequence of commands, when possible
//Return false if and only if no command was pending
static bool drain_queued_commands_P()
{
  char cmd[30];
  if(!queued_commands_P)
    return false;
  // Get the next 30 chars from the sequence of gcodes to run
  strncpy_P(cmd, queued_commands_P, sizeof(cmd)-1);
  cmd[sizeof(cmd)-1]= 0;
  // Look for the end of line, or the end of sequence
  size_t i= 0;
  char c;
  while( (c= cmd[i]) && c!='\n' )
    ++i; // look for the end of this gcode command
  cmd[i]= 0;
  if(enquecommand(cmd)) // buffer was not full (else we will retry later)
  {
    if(c)
      queued_commands_P+= i+1; // move to next command
    else
      queued_commands_P= NULL; // will have no more commands in the sequence
  }
  return true;
}

//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 enquecommands_P(const char* pgcode)
{
    queued_commands_P= pgcode;
    drain_queued_commands_P(); // first command exectuted asap (when possible)
}

//adds a single command to the main command buffer, from RAM
//that is really done in a non-safe way.
//needs overworking someday
//Returns false if it failed to do so
bool enquecommand(const char *cmd)
{
  if(*cmd==';')
    return false;
  if(buflen >= BUFSIZE)
    return false;
  //this is dangerous if a mixing of serial and this happens
  strcpy(&(cmdbuffer[bufindw][0]),cmd);
  SERIAL_ECHO_START;
  SERIAL_ECHOPGM(MSG_Enqueing);
  SERIAL_ECHO(cmdbuffer[bufindw]);
  SERIAL_ECHOLNPGM("\"");
  bufindw= (bufindw + 1)%BUFSIZE;
  buflen += 1;
  return true;
}



void setup_killpin()
{
  #if defined(KILL_PIN) && KILL_PIN > -1
    SET_INPUT(KILL_PIN);
    WRITE(KILL_PIN,HIGH);
  #endif
}

// Set home pin
void setup_homepin(void)
{
#if defined(HOME_PIN) && HOME_PIN > -1
   SET_INPUT(HOME_PIN);
   WRITE(HOME_PIN,HIGH);
#endif
}


void setup_photpin()
{
  #if defined(PHOTOGRAPH_PIN) && PHOTOGRAPH_PIN > -1
    OUT_WRITE(PHOTOGRAPH_PIN, LOW);
  #endif
}

void setup_powerhold()
{
  #if defined(SUICIDE_PIN) && SUICIDE_PIN > -1
    OUT_WRITE(SUICIDE_PIN, HIGH);
  #endif
  #if defined(PS_ON_PIN) && PS_ON_PIN > -1
    #if defined(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 defined(SUICIDE_PIN) && SUICIDE_PIN > -1
    OUT_WRITE(SUICIDE_PIN, LOW);
  #endif
}

void servo_init()
{
  #if (NUM_SERVOS >= 1) && defined(SERVO0_PIN) && (SERVO0_PIN > -1)
    servos[0].attach(SERVO0_PIN);
  #endif
  #if (NUM_SERVOS >= 2) && defined(SERVO1_PIN) && (SERVO1_PIN > -1)
    servos[1].attach(SERVO1_PIN);
  #endif
  #if (NUM_SERVOS >= 3) && defined(SERVO2_PIN) && (SERVO2_PIN > -1)
    servos[2].attach(SERVO2_PIN);
  #endif
  #if (NUM_SERVOS >= 4) && defined(SERVO3_PIN) && (SERVO3_PIN > -1)
    servos[3].attach(SERVO3_PIN);
  #endif
  #if (NUM_SERVOS >= 5)
    #error "TODO: enter initalisation code for more servos"
  #endif

  // Set position of Servo Endstops that are defined
  #ifdef SERVO_ENDSTOPS
  for(int8_t i = 0; i < 3; i++)
  {
    if(servo_endstops[i] > -1) {
      servos[servo_endstops[i]].write(servo_endstop_angles[i * 2 + 1]);
    }
  }
  #endif

  #if SERVO_LEVELING
    delay(PROBE_SERVO_DEACTIVATION_DELAY);
    servos[servo_endstops[Z_AXIS]].detach();
  #endif
}


void setup()
{
  setup_killpin();
  setup_powerhold();
  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_ECHOLNPGM(STRING_VERSION);
  #ifdef STRING_VERSION_CONFIG_H
    #ifdef STRING_CONFIG_H_AUTHOR
      SERIAL_ECHO_START;
      SERIAL_ECHOPGM(MSG_CONFIGURATION_VER);
      SERIAL_ECHOPGM(STRING_VERSION_CONFIG_H);
      SERIAL_ECHOPGM(MSG_AUTHOR);
      SERIAL_ECHOLNPGM(STRING_CONFIG_H_AUTHOR);
      SERIAL_ECHOPGM("Compiled: ");
      SERIAL_ECHOLNPGM(__DATE__);
    #endif // STRING_CONFIG_H_AUTHOR
  #endif // STRING_VERSION_CONFIG_H
  SERIAL_ECHO_START;
  SERIAL_ECHOPGM(MSG_FREE_MEMORY);
  SERIAL_ECHO(freeMemory());
  SERIAL_ECHOPGM(MSG_PLANNER_BUFFER_BYTES);
  SERIAL_ECHOLN((int)sizeof(block_t)*BLOCK_BUFFER_SIZE);
  for(int8_t i = 0; i < BUFSIZE; i++)
  {
    fromsd[i] = false;
  }

  // loads data from EEPROM if available else uses defaults (and resets step acceleration rate)
  Config_RetrieveSettings();

  tp_init();    // Initialize temperature loop
  plan_init();  // Initialize planner;
  watchdog_init();
  st_init();    // Initialize stepper, this enables interrupts!
  setup_photpin();
  servo_init();
  

  lcd_init();
  _delay_ms(1000);  // wait 1sec to display the splash screen

  #if defined(CONTROLLERFAN_PIN) && CONTROLLERFAN_PIN > -1
    SET_OUTPUT(CONTROLLERFAN_PIN); //Set pin used for driver cooling fan
  #endif

  #ifdef DIGIPOT_I2C
    digipot_i2c_init();
  #endif
#ifdef Z_PROBE_SLED
  pinMode(SERVO0_PIN, OUTPUT);
  digitalWrite(SERVO0_PIN, LOW); // turn it off
#endif // Z_PROBE_SLED
  setup_homepin();
  
#ifdef STAT_LED_RED
  pinMode(STAT_LED_RED, OUTPUT);
  digitalWrite(STAT_LED_RED, LOW); // turn it off
#endif
#ifdef STAT_LED_BLUE
  pinMode(STAT_LED_BLUE, OUTPUT);
  digitalWrite(STAT_LED_BLUE, LOW); // turn it off
#endif  
}


void loop()
{
  if(buflen < (BUFSIZE-1))
    get_command();
  #ifdef SDSUPPORT
  card.checkautostart(false);
  #endif
  if(buflen)
  {
    #ifdef SDSUPPORT
      if(card.saving)
      {
        if(strstr_P(cmdbuffer[bufindr], PSTR("M29")) == NULL)
        {
          card.write_command(cmdbuffer[bufindr]);
          if(card.logging)
          {
            process_commands();
          }
          else
          {
            SERIAL_PROTOCOLLNPGM(MSG_OK);
          }
        }
        else
        {
          card.closefile();
          SERIAL_PROTOCOLLNPGM(MSG_FILE_SAVED);
        }
      }
      else
      {
        process_commands();
      }
    #else
      process_commands();
    #endif //SDSUPPORT
    buflen = (buflen-1);
    bufindr = (bufindr + 1)%BUFSIZE;
  }
  //check heater every n milliseconds
  manage_heater();
  manage_inactivity();
  checkHitEndstops();
  lcd_update();
}

void get_command()
{
  if(drain_queued_commands_P()) // priority is given to non-serial commands
    return;
  
  while( MYSERIAL.available() > 0  && buflen < BUFSIZE) {
    serial_char = MYSERIAL.read();
    if(serial_char == '\n' ||
       serial_char == '\r' ||
       serial_count >= (MAX_CMD_SIZE - 1) )
    {
      // end of line == end of comment
      comment_mode = false;

      if(!serial_count) {
        // short cut for empty lines
        return;
      }
      cmdbuffer[bufindw][serial_count] = 0; //terminate string

      fromsd[bufindw] = false;
      if(strchr(cmdbuffer[bufindw], 'N') != NULL)
      {
        strchr_pointer = strchr(cmdbuffer[bufindw], 'N');
        gcode_N = (strtol(strchr_pointer + 1, NULL, 10));
        if(gcode_N != gcode_LastN+1 && (strstr_P(cmdbuffer[bufindw], PSTR("M110")) == NULL) ) {
          SERIAL_ERROR_START;
          SERIAL_ERRORPGM(MSG_ERR_LINE_NO);
          SERIAL_ERRORLN(gcode_LastN);
          //Serial.println(gcode_N);
          FlushSerialRequestResend();
          serial_count = 0;
          return;
        }

        if(strchr(cmdbuffer[bufindw], '*') != NULL)
        {
          byte checksum = 0;
          byte count = 0;
          while(cmdbuffer[bufindw][count] != '*') checksum = checksum^cmdbuffer[bufindw][count++];
          strchr_pointer = strchr(cmdbuffer[bufindw], '*');

          if( (int)(strtod(strchr_pointer + 1, NULL)) != checksum) {
            SERIAL_ERROR_START;
            SERIAL_ERRORPGM(MSG_ERR_CHECKSUM_MISMATCH);
            SERIAL_ERRORLN(gcode_LastN);
            FlushSerialRequestResend();
            serial_count = 0;
            return;
          }
          //if no errors, continue parsing
        }
        else
        {
          SERIAL_ERROR_START;
          SERIAL_ERRORPGM(MSG_ERR_NO_CHECKSUM);
          SERIAL_ERRORLN(gcode_LastN);
          FlushSerialRequestResend();
          serial_count = 0;
          return;
        }

        gcode_LastN = gcode_N;
        //if no errors, continue parsing
      }
      else  // if we don't receive 'N' but still see '*'
      {
        if((strchr(cmdbuffer[bufindw], '*') != NULL))
        {
          SERIAL_ERROR_START;
          SERIAL_ERRORPGM(MSG_ERR_NO_LINENUMBER_WITH_CHECKSUM);
          SERIAL_ERRORLN(gcode_LastN);
          serial_count = 0;
          return;
        }
      }
      if((strchr(cmdbuffer[bufindw], 'G') != NULL)){
        strchr_pointer = strchr(cmdbuffer[bufindw], 'G');
        switch((int)((strtod(strchr_pointer + 1, NULL)))){
        case 0:
        case 1:
        case 2:
        case 3:
          if (Stopped == true) {
            SERIAL_ERRORLNPGM(MSG_ERR_STOPPED);
            LCD_MESSAGEPGM(MSG_STOPPED);
          }
          break;
        default:
          break;
        }

      }

      //If command was e-stop process now
      if(strcmp(cmdbuffer[bufindw], "M112") == 0)
        kill();

      bufindw = (bufindw + 1)%BUFSIZE;
      buflen += 1;

      serial_count = 0; //clear buffer
    }
    else if(serial_char == '\\') {  //Handle escapes
       
        if(MYSERIAL.available() > 0  && buflen < BUFSIZE) {
            // if we have one more character, copy it over
            serial_char = MYSERIAL.read();
            cmdbuffer[bufindw][serial_count++] = serial_char;
        }

        //otherwise do nothing        
    }
    else { // its not a newline, carriage return or escape char
        if(serial_char == ';') comment_mode = true;
        if(!comment_mode) cmdbuffer[bufindw][serial_count++] = serial_char;
    }
  }
  #ifdef SDSUPPORT
  if(!card.sdprinting || serial_count!=0){
    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 ran dry.
  // this character _can_ occur in serial com, due to checksums. however, no checksums are used in SD printing

  static bool stop_buffering=false;
  if(buflen==0) stop_buffering=false;

  while( !card.eof()  && buflen < BUFSIZE && !stop_buffering) {
    int16_t n=card.get();
    serial_char = (char)n;
    if(serial_char == '\n' ||
       serial_char == '\r' ||
       (serial_char == '#' && comment_mode == false) ||
       (serial_char == ':' && comment_mode == false) ||
       serial_count >= (MAX_CMD_SIZE - 1)||n==-1)
    {
      if(card.eof()){
        SERIAL_PROTOCOLLNPGM(MSG_FILE_PRINTED);
        stoptime=millis();
        char time[30];
        unsigned long t=(stoptime-starttime)/1000;
        int hours, minutes;
        minutes=(t/60)%60;
        hours=t/60/60;
        sprintf_P(time, PSTR("%i hours %i minutes"),hours, minutes);
        SERIAL_ECHO_START;
        SERIAL_ECHOLN(time);
        lcd_setstatus(time);
        card.printingHasFinished();
        card.checkautostart(true);

      }
      if(serial_char=='#')
        stop_buffering=true;

      if(!serial_count)
      {
        comment_mode = false; //for new command
        return; //if empty line
      }
      cmdbuffer[bufindw][serial_count] = 0; //terminate string
//      if(!comment_mode){
        fromsd[bufindw] = true;
        buflen += 1;
        bufindw = (bufindw + 1)%BUFSIZE;
//      }
      comment_mode = false; //for new command
      serial_count = 0; //clear buffer
    }
    else
    {
      if(serial_char == ';') comment_mode = true;
      if(!comment_mode) cmdbuffer[bufindw][serial_count++] = serial_char;
    }
  }

  #endif //SDSUPPORT

}


float code_value()
{
  return (strtod(strchr_pointer + 1, NULL));
}

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

bool code_seen(char code)
{
  strchr_pointer = strchr(cmdbuffer[bufindr], code);
  return (strchr_pointer != NULL);  //Return True if a character was found
}

#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[3] =        \
    { 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_retract_mm, HOME_RETRACT_MM);
XYZ_CONSTS_FROM_CONFIG(signed char, home_dir,  HOME_DIR);

#ifdef DUAL_X_CARRIAGE
  #if EXTRUDERS == 1 || defined(COREXY) \
      || !defined(X2_ENABLE_PIN) || !defined(X2_STEP_PIN) || !defined(X2_DIR_PIN) \
      || !defined(X2_HOME_POS) || !defined(X2_MIN_POS) || !defined(X2_MAX_POS) \
      || !defined(X_MAX_PIN) || X_MAX_PIN < 0
    #error "Missing or invalid definitions for DUAL_X_CARRIAGE mode."
  #endif
  #if X_HOME_DIR != -1 || X2_HOME_DIR != 1
    #error "Please use canonical x-carriage assignment" // the x-carriages are defined by their homing directions
  #endif

#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 base_home_pos(X_AXIS) + add_homing[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 (extruder_offset[X_AXIS][1] > 0) ? extruder_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 unsigned long 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
bool extruder_duplication_enabled = false; // used in mode 2
#endif //DUAL_X_CARRIAGE

static void axis_is_at_home(int axis) {
#ifdef DUAL_X_CARRIAGE
  if (axis == X_AXIS) {
    if (active_extruder != 0) {
      current_position[X_AXIS] = x_home_pos(active_extruder);
      min_pos[X_AXIS] =          X2_MIN_POS;
      max_pos[X_AXIS] =          max(extruder_offset[X_AXIS][1], X2_MAX_POS);
      return;
    }
    else if (dual_x_carriage_mode == DXC_DUPLICATION_MODE && active_extruder == 0) {
      current_position[X_AXIS] = base_home_pos(X_AXIS) + add_homing[X_AXIS];
      min_pos[X_AXIS] =          base_min_pos(X_AXIS) + add_homing[X_AXIS];
      max_pos[X_AXIS] =          min(base_max_pos(X_AXIS) + add_homing[X_AXIS],
                                  max(extruder_offset[X_AXIS][1], X2_MAX_POS) - duplicate_extruder_x_offset);
      return;