Independent PID parameters for each extruder

* 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)

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,Kp[e]);
+        EEPROM_WRITE_VAR(i,Ki[e]);
+        EEPROM_WRITE_VAR(i,Kd[e]);
+        #ifdef PID_ADD_EXTRUSION_RATE
+        EEPROM_WRITE_VAR(i,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_ECHOLN(""); 
-#endif
+	for (int e = 0; e < EXTRUDERS; e++)
+	{
+	  SERIAL_ECHO_START;
+      SERIAL_ECHOPAIR("   M301 E", (long unsigned int)e);
+	  SERIAL_ECHOPAIR(" P", Kp[e]);
+      SERIAL_ECHOPAIR(" I" ,unscalePID_i(Ki[e])); 
+      SERIAL_ECHOPAIR(" D" ,unscalePID_d(Kd[e]));
+#ifdef PID_ADD_EXTRUSION_RATE
+      SERIAL_ECHOPAIR(" C" ,Kc[e]);
+#endif//PID_ADD_EXTRUSION_RATE	  
+      SERIAL_ECHOLN(""); 
+	}
+#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,Kp[e]);
+            EEPROM_READ_VAR(i,Ki[e]);
+		    EEPROM_READ_VAR(i,Kd[e]);
+#ifdef PID_ADD_EXTRUSION_RATE
+            EEPROM_READ_VAR(i,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]=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);
-    
-    // call updatePID (similar to when we have processed M301)
-    updatePID();
-    
+	for (int e = 0; e < EXTRUDERS; e++)
+	{
+      Kp[e] = DEFAULT_Kp;
+      Ki[e] = scalePID_i(DEFAULT_Ki);
+      Kd[e] = scalePID_d(DEFAULT_Kd);
 #ifdef PID_ADD_EXTRUSION_RATE
-    Kc = DEFAULT_Kc;
+      Kc[e] = DEFAULT_Kc;
 #endif//PID_ADD_EXTRUSION_RATE
+    }
+    // call updatePID (similar to when we have processed M301)
+    updatePID();
 #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')) Kp[e] = code_value();
+			if (code_seen('I')) Ki[e] = scalePID_i(code_value());
+			if (code_seen('D')) Kd[e] = scalePID_d(code_value());
+			#ifdef PID_ADD_EXTRUSION_RATE
+			if (code_seen('C')) Kc[e] = code_value();
+			#endif			
+
+			updatePID();
+			SERIAL_PROTOCOL(MSG_OK);
+			SERIAL_PROTOCOL(" e:"); // specify extruder in serial output
+			SERIAL_PROTOCOL(e);
+			SERIAL_PROTOCOL(" p:");
+			SERIAL_PROTOCOL(Kp[e]);
+			SERIAL_PROTOCOL(" i:");
+			SERIAL_PROTOCOL(unscalePID_i(Ki[e]));
+			SERIAL_PROTOCOL(" d:");
+			SERIAL_PROTOCOL(unscalePID_d(Kd[e]));
+			#ifdef PID_ADD_EXTRUSION_RATE
+			SERIAL_PROTOCOL(" c:");
+			//Kc does not have scaling applied above, or in resetting defaults
+			SERIAL_PROTOCOL(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/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
+  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
+#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 / Ki[e];  
   }
 #endif
 #ifdef PIDTEMPBED
             temp_iState[e] = 0.0;
             pid_reset[e] = false;
           }
-          pTerm[e] = Kp * pid_error[e];
+          pTerm[e] = 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] = 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] = (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 / Ki[e];
 #endif //PIDTEMP
 #ifdef PIDTEMPBED
     temp_iState_min_bed = 0.0;

Marlin/temperature.h

 #endif
 
 #ifdef PIDTEMP
-  extern float Kp,Ki,Kd,Kc;
+  extern float Kp[EXTRUDERS], Ki[EXTRUDERS], Kd[EXTRUDERS], Kc[EXTRUDERS];
   float scalePID_i(float i);
   float scalePID_d(float d);
   float unscalePID_i(float i);