Merge pull request #1344 from grob6000/independent_pid

Independent PID parameters for each extruder

Marlin/Configuration.h

   //#define PID_DEBUG // Sends debug data to the serial port.
   //#define PID_OPENLOOP 1 // Puts PID in open loop. M104/M140 sets the output power from 0 to PID_MAX
   //#define SLOW_PWM_HEATERS // PWM with very low frequency (roughly 0.125Hz=8s) and minimum state time of approximately 1s useful for heaters driven by a relay
+  //#define PID_PARAMS_PER_EXTRUDER // Uses separate PID parameters for each extruder (useful for mismatched extruders)
+                                    // Set/get with gcode: M301 E[extruder number, 0-2]
   #define PID_FUNCTIONAL_RANGE 10 // If the temperature difference between the target temperature and the actual temperature
                                   // is more then PID_FUNCTIONAL_RANGE then the PID will be shut off and the heater will be set to min/max.
   #define PID_INTEGRAL_DRIVE_MAX PID_MAX  //limit for the integral term

Marlin/ConfigurationStore.cpp

 // wrong data being written to the variables.
 // ALSO:  always make sure the variables in the Store and retrieve sections are in the same order.
 
-#define EEPROM_VERSION "V13"
+#define EEPROM_VERSION "V14"
 
 #ifdef EEPROM_SETTINGS
 void Config_StoreSettings() 
   EEPROM_WRITE_VAR(i,delta_radius);
   EEPROM_WRITE_VAR(i,delta_diagonal_rod);
   EEPROM_WRITE_VAR(i,delta_segments_per_second);
-  #endif
+  #endif//DELTA
   #ifndef ULTIPANEL
   int plaPreheatHotendTemp = PLA_PREHEAT_HOTEND_TEMP, plaPreheatHPBTemp = PLA_PREHEAT_HPB_TEMP, plaPreheatFanSpeed = PLA_PREHEAT_FAN_SPEED;
   int absPreheatHotendTemp = ABS_PREHEAT_HOTEND_TEMP, absPreheatHPBTemp = ABS_PREHEAT_HPB_TEMP, absPreheatFanSpeed = ABS_PREHEAT_FAN_SPEED;
-  #endif
+  #endif//ULTIPANEL
   EEPROM_WRITE_VAR(i,plaPreheatHotendTemp);
   EEPROM_WRITE_VAR(i,plaPreheatHPBTemp);
   EEPROM_WRITE_VAR(i,plaPreheatFanSpeed);
   EEPROM_WRITE_VAR(i,absPreheatFanSpeed);
   EEPROM_WRITE_VAR(i,zprobe_zoffset);
   #ifdef PIDTEMP
-    EEPROM_WRITE_VAR(i,Kp);
-    EEPROM_WRITE_VAR(i,Ki);
-    EEPROM_WRITE_VAR(i,Kd);
-  #else
+    float dummy = 0.0f;
+    for (int e = 0; e < 3; e++)
+	{
+	  if (e < EXTRUDERS)
+	  {
+        EEPROM_WRITE_VAR(i,PID_PARAM(Kp,e));
+        EEPROM_WRITE_VAR(i,PID_PARAM(Ki,e));
+        EEPROM_WRITE_VAR(i,PID_PARAM(Kd,e));
+        #ifdef PID_ADD_EXTRUSION_RATE
+        EEPROM_WRITE_VAR(i,PID_PARAM(Kc,e));
+        #else//PID_ADD_EXTRUSION_RATE
+		dummy = 1.0f; // 1.0 = default kc
+	    EEPROM_WRITE_VAR(dummmy);
+        #endif//PID_ADD_EXTRUSION_RATE
+	  }
+	  else
+	  {
+		dummy = 3000.0f;
+	    EEPROM_WRITE_VAR(i, dummy);
+		dummy = 0.0f;
+        EEPROM_WRITE_VAR(i,dummy);
+        EEPROM_WRITE_VAR(i,dummy);
+	  }
+	}
+  #else//PIDTEMP
 		float dummy = 3000.0f;
     EEPROM_WRITE_VAR(i,dummy);
 		dummy = 0.0f;
     EEPROM_WRITE_VAR(i,dummy);
     EEPROM_WRITE_VAR(i,dummy);
-  #endif
+  #endif//PIDTEMP
   #ifndef DOGLCD
     int lcd_contrast = 32;
-  #endif
+  #endif//DOGLCD
   EEPROM_WRITE_VAR(i,lcd_contrast);
   #ifdef SCARA
   EEPROM_WRITE_VAR(i,axis_scaling);        // Add scaling for SCARA
-  #endif
+  #endif//SCARA
   #ifdef FWRETRACT
   EEPROM_WRITE_VAR(i,autoretract_enabled);
   EEPROM_WRITE_VAR(i,retract_length);
   #if EXTRUDERS > 1
   EEPROM_WRITE_VAR(i,retract_length_swap);
-  #endif
+  #endif//EXTRUDERS > 1
   EEPROM_WRITE_VAR(i,retract_feedrate);
   EEPROM_WRITE_VAR(i,retract_zlift);
   EEPROM_WRITE_VAR(i,retract_recover_length);
   #if EXTRUDERS > 1
   EEPROM_WRITE_VAR(i,retract_recover_length_swap);
-  #endif
+  #endif//EXTRUDERS > 1
   EEPROM_WRITE_VAR(i,retract_recover_feedrate);
-  #endif
+  #endif//FWRETRACT
 
   // Save filament sizes
   EEPROM_WRITE_VAR(i, volumetric_enabled);
   EEPROM_WRITE_VAR(i, filament_size[1]);
   #if EXTRUDERS > 2
   EEPROM_WRITE_VAR(i, filament_size[2]);
-  #endif
-  #endif
+  #endif//EXTRUDERS > 2
+  #endif//EXTRUDERS > 1
   
   char ver2[4]=EEPROM_VERSION;
   i=EEPROM_OFFSET;
     SERIAL_ECHOLN("");
       
     SERIAL_ECHO_START;
-#endif
+#endif//SCARA
     SERIAL_ECHOLNPGM("Maximum feedrates (mm/s):");
     SERIAL_ECHO_START;
     SERIAL_ECHOPAIR("  M203 X", max_feedrate[X_AXIS]);
 	SERIAL_ECHOPAIR(" R" ,delta_radius );
 	SERIAL_ECHOPAIR(" S" ,delta_segments_per_second );
 	SERIAL_ECHOLN("");
-#endif
+#endif//DELTA
 #ifdef PIDTEMP
     SERIAL_ECHO_START;
     SERIAL_ECHOLNPGM("PID settings:");
-    SERIAL_ECHO_START;
-    SERIAL_ECHOPAIR("   M301 P",Kp); 
-    SERIAL_ECHOPAIR(" I" ,unscalePID_i(Ki)); 
-    SERIAL_ECHOPAIR(" D" ,unscalePID_d(Kd));
+	SERIAL_ECHO_START;
+    SERIAL_ECHOPAIR("   M301 P", PID_PARAM(Kp,0)); // for compatibility with hosts, only echos values for E0
+	SERIAL_ECHOPAIR(" I", unscalePID_i(PID_PARAM(Ki, 0)));
+	SERIAL_ECHOPAIR(" D", unscalePID_d(PID_PARAM(Kd, 0)));
     SERIAL_ECHOLN(""); 
-#endif
+#endif//PIDTEMP
 #ifdef FWRETRACT
     SERIAL_ECHO_START;
     SERIAL_ECHOLNPGM("Retract: S=Length (mm) F:Speed (mm/m) Z: ZLift (mm)");
     SERIAL_ECHO_START;
     SERIAL_ECHOPAIR("   Swap rec. addl. length (mm): ", retract_recover_length_swap);
     SERIAL_ECHOLN("");
-#endif
+#endif//EXTRUDERS > 1
     SERIAL_ECHO_START;
     if (volumetric_enabled) {
         SERIAL_ECHOLNPGM("Filament settings:");
 		SERIAL_ECHO_START;
         SERIAL_ECHOPAIR("   M200 T2 D", filament_size[2]);
 		SERIAL_ECHOLN("");
-#endif
-#endif
+#endif//EXTRUDERS > 2
+#endif//EXTRUDERS > 1
     } else {
         SERIAL_ECHOLNPGM("Filament settings: Disabled");
     }
-#endif
+#endif//FWRETRACT
 }
-#endif
+#endif//DISABLE_M503
 
 
 #ifdef EEPROM_SETTINGS
 		EEPROM_READ_VAR(i,delta_radius);
 		EEPROM_READ_VAR(i,delta_diagonal_rod);
 		EEPROM_READ_VAR(i,delta_segments_per_second);
-        #endif
+        #endif//DELTA
         #ifndef ULTIPANEL
         int plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed;
         int absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed;
-        #endif
+        #endif//ULTIPANEL
         EEPROM_READ_VAR(i,plaPreheatHotendTemp);
         EEPROM_READ_VAR(i,plaPreheatHPBTemp);
         EEPROM_READ_VAR(i,plaPreheatFanSpeed);
         EEPROM_READ_VAR(i,absPreheatHPBTemp);
         EEPROM_READ_VAR(i,absPreheatFanSpeed);
         EEPROM_READ_VAR(i,zprobe_zoffset);
-        #ifndef PIDTEMP
-        float Kp,Ki,Kd;
-        #endif
-        // do not need to scale PID values as the values in EEPROM are already scaled		
-        EEPROM_READ_VAR(i,Kp);
-        EEPROM_READ_VAR(i,Ki);
-        EEPROM_READ_VAR(i,Kd);
+        #ifdef PIDTEMP
+		float dummy = 0.0f;
+		for (int e = 0; e < 3; e++) // 3 = max extruders supported by marlin
+		{
+		  if (e < EXTRUDERS)
+		  {
+		    // do not need to scale PID values as the values in EEPROM are already scaled			  
+            EEPROM_READ_VAR(i,PID_PARAM(Kp,e));
+            EEPROM_READ_VAR(i,PID_PARAM(Ki,e));
+		    EEPROM_READ_VAR(i,PID_PARAM(Kd,e));
+#ifdef PID_ADD_EXTRUSION_RATE
+            EEPROM_READ_VAR(i,PID_PARAM(Kc,e));
+#else//PID_ADD_EXTRUSION_RATE
+	        EEPROM_READ_VAR(i,dummy);
+#endif//PID_ADD_EXTRUSION_RATE
+		  }
+		  else
+		  {
+			EEPROM_READ_VAR(i,dummy);
+			EEPROM_READ_VAR(i,dummy);
+			EEPROM_READ_VAR(i,dummy);
+			EEPROM_READ_VAR(i,dummy);
+		  }
+		}
+		#else//PIDTEMP
+		// 4 x 3 = 12 slots for PID parameters
+		float dummy = 0.0f;
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);
+		EEPROM_READ_VAR(i,dummy);			
+		#endif//PIDTEMP
         #ifndef DOGLCD
         int lcd_contrast;
-        #endif
+        #endif//DOGLCD
         EEPROM_READ_VAR(i,lcd_contrast);
 		#ifdef SCARA
 		EEPROM_READ_VAR(i,axis_scaling);
-		#endif
+		#endif//SCARA
 
 		#ifdef FWRETRACT
 		EEPROM_READ_VAR(i,autoretract_enabled);
 		EEPROM_READ_VAR(i,retract_length);
 		#if EXTRUDERS > 1
 		EEPROM_READ_VAR(i,retract_length_swap);
-		#endif
+		#endif//EXTRUDERS > 1
 		EEPROM_READ_VAR(i,retract_feedrate);
 		EEPROM_READ_VAR(i,retract_zlift);
 		EEPROM_READ_VAR(i,retract_recover_length);
 		#if EXTRUDERS > 1
 		EEPROM_READ_VAR(i,retract_recover_length_swap);
-		#endif
+		#endif//EXTRUDERS > 1
 		EEPROM_READ_VAR(i,retract_recover_feedrate);
-		#endif
+		#endif//FWRETRACT
 
 		EEPROM_READ_VAR(i, volumetric_enabled);
 		EEPROM_READ_VAR(i, filament_size[0]);
 		EEPROM_READ_VAR(i, filament_size[1]);
 #if EXTRUDERS > 2
 		EEPROM_READ_VAR(i, filament_size[2]);
-#endif
-#endif
+#endif//EXTRUDERS > 2
+#endif//EXTRUDERS > 1
 		calculate_volumetric_multipliers();
 		// Call updatePID (similar to when we have processed M301)
 		updatePID();
     }
     #ifdef EEPROM_CHITCHAT
       Config_PrintSettings();
-    #endif
+    #endif//EEPROM_CHITCHAT
 }
-#endif
+#endif//EEPROM_SETTINGS
 
 void Config_ResetDefault()
 {
         max_acceleration_units_per_sq_second[i]=pgm_read_float(&tmp3[i]);
 		#ifdef SCARA
 		axis_scaling[i]=1;
-		#endif
+		#endif//SCARA
     }
     
     // steps per sq second need to be updated to agree with the units per sq second
 	delta_diagonal_rod= DELTA_DIAGONAL_ROD;
 	delta_segments_per_second= DELTA_SEGMENTS_PER_SECOND;
 	recalc_delta_settings(delta_radius, delta_diagonal_rod);
-#endif
+#endif//DELTA
 #ifdef ULTIPANEL
     plaPreheatHotendTemp = PLA_PREHEAT_HOTEND_TEMP;
     plaPreheatHPBTemp = PLA_PREHEAT_HPB_TEMP;
     absPreheatHotendTemp = ABS_PREHEAT_HOTEND_TEMP;
     absPreheatHPBTemp = ABS_PREHEAT_HPB_TEMP;
     absPreheatFanSpeed = ABS_PREHEAT_FAN_SPEED;
-#endif
+#endif//ULTIPANEL
 #ifdef ENABLE_AUTO_BED_LEVELING
     zprobe_zoffset = -Z_PROBE_OFFSET_FROM_EXTRUDER;
-#endif
+#endif//ENABLE_AUTO_BED_LEVELING
 #ifdef DOGLCD
     lcd_contrast = DEFAULT_LCD_CONTRAST;
-#endif
+#endif//DOGLCD
 #ifdef PIDTEMP
-    Kp = DEFAULT_Kp;
-    Ki = scalePID_i(DEFAULT_Ki);
-    Kd = scalePID_d(DEFAULT_Kd);
-    
+#ifdef PID_PARAMS_PER_EXTRUDER
+	for (int e = 0; e < EXTRUDERS; e++)
+#else // PID_PARAMS_PER_EXTRUDER
+	int e = 0; // only need to write once
+#endif // PID_PARAMS_PER_EXTRUDER
+	{
+      PID_PARAM(Kp,e) = DEFAULT_Kp;
+      PID_PARAM(Ki,e) = scalePID_i(DEFAULT_Ki);
+      PID_PARAM(Kd,e) = scalePID_d(DEFAULT_Kd);
+      #ifdef PID_ADD_EXTRUSION_RATE
+        PID_PARAM(Kc,e) = DEFAULT_Kc;
+      #endif//PID_ADD_EXTRUSION_RATE
+    }
     // call updatePID (similar to when we have processed M301)
     updatePID();
-    
-#ifdef PID_ADD_EXTRUSION_RATE
-    Kc = DEFAULT_Kc;
-#endif//PID_ADD_EXTRUSION_RATE
 #endif//PIDTEMP
 
 #ifdef FWRETRACT
 	retract_length = RETRACT_LENGTH;
 #if EXTRUDERS > 1
 	retract_length_swap = RETRACT_LENGTH_SWAP;
-#endif
+#endif//EXTRUDERS > 1
 	retract_feedrate = RETRACT_FEEDRATE;
 	retract_zlift = RETRACT_ZLIFT;
 	retract_recover_length = RETRACT_RECOVER_LENGTH;
 #if EXTRUDERS > 1
 	retract_recover_length_swap = RETRACT_RECOVER_LENGTH_SWAP;
-#endif
+#endif//EXTRUDERS > 1
 	retract_recover_feedrate = RETRACT_RECOVER_FEEDRATE;
-#endif
+#endif//FWRETRACT
 
 	volumetric_enabled = false;
 	filament_size[0] = DEFAULT_NOMINAL_FILAMENT_DIA;
 	filament_size[1] = DEFAULT_NOMINAL_FILAMENT_DIA;
 #if EXTRUDERS > 2
 	filament_size[2] = DEFAULT_NOMINAL_FILAMENT_DIA;
-#endif
-#endif
+#endif//EXTRUDERS > 2
+#endif//EXTRUDERS > 1
 	calculate_volumetric_multipliers();
 
 SERIAL_ECHO_START;
 SERIAL_ECHOLNPGM("Hardcoded Default Settings Loaded");
 
-}
+}

Marlin/Marlin_main.cpp

     #endif // M300
 
     #ifdef PIDTEMP
-    case 301: // M301
-      {
-        if(code_seen('P')) Kp = code_value();
-        if(code_seen('I')) Ki = scalePID_i(code_value());
-        if(code_seen('D')) Kd = scalePID_d(code_value());
+	case 301: // M301
+	{
 
-        #ifdef PID_ADD_EXTRUSION_RATE
-        if(code_seen('C')) Kc = code_value();
-        #endif
+		// 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 = 0; // extruder being updated
+		if (code_seen('E'))
+		{
+			e = (int)code_value();
+		}
+		if (e < EXTRUDERS) // catch bad input value
+		{
+
+			if (code_seen('P')) PID_PARAM(Kp,e) = code_value();
+			if (code_seen('I')) PID_PARAM(Ki,e) = scalePID_i(code_value());
+			if (code_seen('D')) PID_PARAM(Kd,e) = scalePID_d(code_value());
+			#ifdef PID_ADD_EXTRUSION_RATE
+			if (code_seen('C')) PID_PARAM(Kc,e) = code_value();
+			#endif			
+
+			updatePID();
+			SERIAL_PROTOCOL(MSG_OK);
+            #ifdef PID_PARAMS_PER_EXTRUDER
+			  SERIAL_PROTOCOL(" e:"); // specify extruder in serial output
+			  SERIAL_PROTOCOL(e);
+            #endif // PID_PARAMS_PER_EXTRUDER
+			SERIAL_PROTOCOL(" p:");
+			SERIAL_PROTOCOL(PID_PARAM(Kp,e));
+			SERIAL_PROTOCOL(" i:");
+			SERIAL_PROTOCOL(unscalePID_i(PID_PARAM(Ki,e)));
+			SERIAL_PROTOCOL(" d:");
+			SERIAL_PROTOCOL(unscalePID_d(PID_PARAM(Kd,e)));
+			#ifdef PID_ADD_EXTRUSION_RATE
+			SERIAL_PROTOCOL(" c:");
+			//Kc does not have scaling applied above, or in resetting defaults
+			SERIAL_PROTOCOL(PID_PARAM(Kc,e));
+			#endif
+			SERIAL_PROTOCOLLN("");
+		
+		}
+		else
+		{
+			SERIAL_ECHO_START;
+			SERIAL_ECHOLN(MSG_INVALID_EXTRUDER);
+		}
 
-        updatePID();
-        SERIAL_PROTOCOL(MSG_OK);
-        SERIAL_PROTOCOL(" p:");
-        SERIAL_PROTOCOL(Kp);
-        SERIAL_PROTOCOL(" i:");
-        SERIAL_PROTOCOL(unscalePID_i(Ki));
-        SERIAL_PROTOCOL(" d:");
-        SERIAL_PROTOCOL(unscalePID_d(Kd));
-        #ifdef PID_ADD_EXTRUSION_RATE
-        SERIAL_PROTOCOL(" c:");
-        //Kc does not have scaling applied above, or in resetting defaults
-        SERIAL_PROTOCOL(Kc);
-        #endif
-        SERIAL_PROTOCOLLN("");
       }
       break;
     #endif //PIDTEMP

Marlin/language_ca.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Accel"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_de.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Acc"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_en.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Accel"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_es.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Acel"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_eu.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Azelerazioa"
 #define MSG_VXY_JERK                        "Vxy-astindua"
 #define MSG_VZ_JERK                         "Vz-astindua"

Marlin/language_fi.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Kiihtyv"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_fr.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Accel"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_it.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Accel."
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_nl.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Versn"
 #define MSG_VXY_JERK                        "Vxy-jerk"
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_pl.h

 #define MSG_PID_I                           "PID-I"
 #define MSG_PID_D                           "PID-D"
 #define MSG_PID_C                           "PID-C"
+#define MSG_PID_P1                          "PID-P E2"
+#define MSG_PID_I1                          "PID-I E2"
+#define MSG_PID_D1                          "PID-D E2"
+#define MSG_PID_C1                          "PID-C E2"
+#define MSG_PID_P2                          "PID-P E3"
+#define MSG_PID_I2                          "PID-I E3"
+#define MSG_PID_D2                          "PID-D E3"
+#define MSG_PID_C2                          "PID-C E3"
 #define MSG_ACC                             "Przyspieszenie"
 #define MSG_VXY_JERK                        "Zryw Vxy"
 #define MSG_VZ_JERK                         "Zryw Vz"

Marlin/language_pt.h

 #define MSG_PID_I                           "PID-I: "
 #define MSG_PID_D                           "PID-D: "
 #define MSG_PID_C                           "PID-C: "
+#define MSG_PID_P1                          "PID-P E2: "
+#define MSG_PID_I1                          "PID-I E2: "
+#define MSG_PID_D1                          "PID-D E2: "
+#define MSG_PID_C1                          "PID-C E2: "
+#define MSG_PID_P2                          "PID-P E3: "
+#define MSG_PID_I2                          "PID-I E3: "
+#define MSG_PID_D2                          "PID-D E3: "
+#define MSG_PID_C2                          "PID-C E3: "
 #define MSG_ACC                             "Acc:"
 #define MSG_VXY_JERK                        "Vxy-jerk: "
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/language_ru.h

 #define MSG_PID_I                           "PID-I: "
 #define MSG_PID_D                           "PID-D: "
 #define MSG_PID_C                           "PID-C: "
+#define MSG_PID_P1                          "PID-P E2: "
+#define MSG_PID_I1                          "PID-I E2: "
+#define MSG_PID_D1                          "PID-D E2: "
+#define MSG_PID_C1                          "PID-C E2: "
+#define MSG_PID_P2                          "PID-P E3: "
+#define MSG_PID_I2                          "PID-I E3: "
+#define MSG_PID_D2                          "PID-D E3: "
+#define MSG_PID_C2                          "PID-C E3: "
 #define MSG_ACC                             "Acc:"
 #define MSG_VXY_JERK                        "Vxy-jerk: "
 #define MSG_VZ_JERK                         "Vz-jerk"

Marlin/temperature.cpp

   int redundant_temperature_raw = 0;
   float redundant_temperature = 0.0;
 #endif
-#ifdef PIDTEMP
-  float Kp=DEFAULT_Kp;
-  float Ki=(DEFAULT_Ki*PID_dT);
-  float Kd=(DEFAULT_Kd/PID_dT);
-  #ifdef PID_ADD_EXTRUSION_RATE
-    float Kc=DEFAULT_Kc;
-  #endif
-#endif //PIDTEMP
 
 #ifdef PIDTEMPBED
   float bedKp=DEFAULT_bedKp;
   # define ARRAY_BY_EXTRUDERS(v1, v2, v3) { v1 }
 #endif
 
+#ifdef PIDTEMP
+#ifdef PID_PARAMS_PER_EXTRUDER
+  float Kp[EXTRUDERS] = ARRAY_BY_EXTRUDERS(DEFAULT_Kp, DEFAULT_Kp, DEFAULT_Kp);
+  float Ki[EXTRUDERS] = ARRAY_BY_EXTRUDERS(DEFAULT_Ki*PID_dT, DEFAULT_Ki*PID_dT, DEFAULT_Ki*PID_dT);
+  float Kd[EXTRUDERS] = ARRAY_BY_EXTRUDERS(DEFAULT_Kd / PID_dT, DEFAULT_Kd / PID_dT, DEFAULT_Kd / PID_dT);
+  #ifdef PID_ADD_EXTRUSION_RATE
+    float Kc[EXTRUDERS] = ARRAY_BY_EXTRUDERS(DEFAULT_Kc, DEFAULT_Kc, DEFAULT_Kc);
+  #endif // PID_ADD_EXTRUSION_RATE
+#else //PID_PARAMS_PER_EXTRUDER
+  float Kp = DEFAULT_Kp;
+  float Ki = DEFAULT_Ki * PID_dT;
+  float Kd = DEFAULT_Kd / PID_dT;
+  #ifdef PID_ADD_EXTRUSION_RATE
+    float Kc = DEFAULT_Kc;
+  #endif // PID_ADD_EXTRUSION_RATE
+#endif // PID_PARAMS_PER_EXTRUDER
+#endif //PIDTEMP
+
 // Init min and max temp with extreme values to prevent false errors during startup
 static int minttemp_raw[EXTRUDERS] = ARRAY_BY_EXTRUDERS( HEATER_0_RAW_LO_TEMP , HEATER_1_RAW_LO_TEMP , HEATER_2_RAW_LO_TEMP );
 static int maxttemp_raw[EXTRUDERS] = ARRAY_BY_EXTRUDERS( HEATER_0_RAW_HI_TEMP , HEATER_1_RAW_HI_TEMP , HEATER_2_RAW_HI_TEMP );
 {
 #ifdef PIDTEMP
   for(int e = 0; e < EXTRUDERS; e++) { 
-     temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / Ki;  
+     temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / PID_PARAM(Ki,e);  
   }
 #endif
 #ifdef PIDTEMPBED
             temp_iState[e] = 0.0;
             pid_reset[e] = false;
           }
-          pTerm[e] = Kp * pid_error[e];
+          pTerm[e] = PID_PARAM(Kp,e) * pid_error[e];
           temp_iState[e] += pid_error[e];
           temp_iState[e] = constrain(temp_iState[e], temp_iState_min[e], temp_iState_max[e]);
-          iTerm[e] = Ki * temp_iState[e];
+          iTerm[e] = PID_PARAM(Ki,e) * temp_iState[e];
 
           //K1 defined in Configuration.h in the PID settings
           #define K2 (1.0-K1)
-          dTerm[e] = (Kd * (pid_input - temp_dState[e]))*K2 + (K1 * dTerm[e]);
+          dTerm[e] = (PID_PARAM(Kd,e) * (pid_input - temp_dState[e]))*K2 + (K1 * dTerm[e]);
           pid_output = pTerm[e] + iTerm[e] - dTerm[e];
           if (pid_output > PID_MAX) {
             if (pid_error[e] > 0 )  temp_iState[e] -= pid_error[e]; // conditional un-integration
     maxttemp[e] = maxttemp[0];
 #ifdef PIDTEMP
     temp_iState_min[e] = 0.0;
-    temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / Ki;
+    temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / PID_PARAM(Ki,e);
 #endif //PIDTEMP
 #ifdef PIDTEMPBED
     temp_iState_min_bed = 0.0;

Marlin/temperature.h

 #endif
 
 #ifdef PIDTEMP
-  extern float Kp,Ki,Kd,Kc;
+
+  #ifdef PID_PARAMS_PER_EXTRUDER
+    extern float Kp[EXTRUDERS], Ki[EXTRUDERS], Kd[EXTRUDERS], Kc[EXTRUDERS]; // one param per extruder
+    #define PID_PARAM(param,e) param[e] // use macro to point to array value
+  #else
+    extern float Kp, Ki, Kd, Kc; // one param per extruder - saves 20 or 36 bytes of ram (inc array pointer)
+    #define PID_PARAM(param, e) param // use macro to point directly to value
+  #endif // PID_PARAMS_PER_EXTRUDER	
   float scalePID_i(float i);
   float scalePID_d(float d);
   float unscalePID_i(float i);

Marlin/ultralcd.cpp

 int32_t minEditValue, maxEditValue;
 menuFunc_t callbackFunc;
 
-// place-holders for Ki and Kd edits
+// place-holders for Ki and Kd edits, and the extruder # being edited
 float raw_Ki, raw_Kd;
+int pid_current_extruder;
 
 static void lcd_goto_menu(menuFunc_t menu, const uint32_t encoder=0, const bool feedback=true) {
   if (currentMenu != menu) {
 
 static void lcd_control_temperature_menu()
 {
-#ifdef PIDTEMP
-    // set up temp variables - undo the default scaling
-    raw_Ki = unscalePID_i(Ki);
-    raw_Kd = unscalePID_d(Kd);
-#endif
-
     START_MENU();
     MENU_ITEM(back, MSG_CONTROL, lcd_control_menu);
 #if TEMP_SENSOR_0 != 0
     MENU_ITEM_EDIT(float32, MSG_FACTOR, &autotemp_factor, 0.0, 1.0);
 #endif
 #ifdef PIDTEMP
-    MENU_ITEM_EDIT(float52, MSG_PID_P, &Kp, 1, 9990);
-    // i is typically a small value so allows values below 1
-    MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_I, &raw_Ki, 0.01, 9990, copy_and_scalePID_i);
-    MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_D, &raw_Kd, 1, 9990, copy_and_scalePID_d);
-# ifdef PID_ADD_EXTRUSION_RATE
-    MENU_ITEM_EDIT(float3, MSG_PID_C, &Kc, 1, 9990);
-# endif//PID_ADD_EXTRUSION_RATE
+	// set up temp variables - undo the default scaling
+	pid_current_extruder = 0;
+	raw_Ki = unscalePID_i(PID_PARAM(Ki,0));
+	raw_Kd = unscalePID_d(PID_PARAM(Kd,0));
+	MENU_ITEM_EDIT(float52, MSG_PID_P, &PID_PARAM(Kp,0), 1, 9990);
+	// i is typically a small value so allows values below 1
+	MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_I, &raw_Ki, 0.01, 9990, copy_and_scalePID_i);
+	MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_D, &raw_Kd, 1, 9990, copy_and_scalePID_d);
+    #ifdef PID_ADD_EXTRUSION_RATE
+	  MENU_ITEM_EDIT(float3, MSG_PID_C, &PID_PARAM(Kc,0), 1, 9990);
+    #endif//PID_ADD_EXTRUSION_RATE
+#ifdef PID_PARAMS_PER_EXTRUDER
+  #if EXTRUDERS > 1
+	  // set up temp variables - undo the default scaling
+	  pid_current_extruder = 0;
+	  raw_Ki = unscalePID_i(PID_PARAM(Ki,1));
+	  raw_Kd = unscalePID_d(PID_PARAM(Kd,1));
+	  MENU_ITEM_EDIT(float52, MSG_PID_P1, &PID_PARAM(Kp,1), 1, 9990);
+	  // i is typically a small value so allows values below 1
+	  MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_I1, &raw_Ki, 0.01, 9990, copy_and_scalePID_i);
+	  MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_D1, &raw_Kd, 1, 9990, copy_and_scalePID_d);
+      #ifdef PID_ADD_EXTRUSION_RATE
+	    MENU_ITEM_EDIT(float3, MSG_PID_C1, &PID_PARAM(Kc,1), 1, 9990);
+      #endif//PID_ADD_EXTRUSION_RATE
+  #endif//EXTRUDERS > 1
+  #if EXTRUDERS > 2
+	    // set up temp variables - undo the default scaling
+	    pid_current_extruder = 0;
+	    raw_Ki = unscalePID_i(PID_PARAM(Ki,2));
+	    raw_Kd = unscalePID_d(PID_PARAM(Kd,2));
+	    MENU_ITEM_EDIT(float52, MSG_PID_P2, &PID_PARAM(Kp,2), 1, 9990);
+	    // i is typically a small value so allows values below 1
+	    MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_I2, &raw_Ki, 0.01, 9990, copy_and_scalePID_i);
+	    MENU_ITEM_EDIT_CALLBACK(float52, MSG_PID_D2, &raw_Kd, 1, 9990, copy_and_scalePID_d);
+        #ifdef PID_ADD_EXTRUSION_RATE
+	      MENU_ITEM_EDIT(float3, MSG_PID_C2, &PID_PARAM(Kc,2), 1, 9990);
+        #endif//PID_ADD_EXTRUSION_RATE
+  #endif//EXTRUDERS > 2
+#endif // PID_PARAMS_PER_EXTRUDER
 #endif//PIDTEMP
     MENU_ITEM(submenu, MSG_PREHEAT_PLA_SETTINGS, lcd_control_temperature_preheat_pla_settings_menu);
     MENU_ITEM(submenu, MSG_PREHEAT_ABS_SETTINGS, lcd_control_temperature_preheat_abs_settings_menu);
 void copy_and_scalePID_i()
 {
 #ifdef PIDTEMP
-  Ki = scalePID_i(raw_Ki);
+  PID_PARAM(Ki, pid_current_extruder) = scalePID_i(raw_Ki);
   updatePID();
 #endif
 }
 void copy_and_scalePID_d()
 {
 #ifdef PIDTEMP
-  Kd = scalePID_d(raw_Kd);
+	PID_PARAM(Kd, pid_current_extruder) = scalePID_d(raw_Kd);
   updatePID();
 #endif
 }