Make multiple PID parameters a config option

* 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.

Marlin/Configuration.h

@@ -152,6 +152,8 @@
   //#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

@@ -81,11 +81,11 @@ void Config_StoreSettings()
 	{
 	  if (e < EXTRUDERS)
 	  {
-        EEPROM_WRITE_VAR(i,Kp[e]);
+        EEPROM_WRITE_VAR(i,PID_PARAM(Kp,e));
-        EEPROM_WRITE_VAR(i,Ki[e]);
+        EEPROM_WRITE_VAR(i,PID_PARAM(Ki,e));
-        EEPROM_WRITE_VAR(i,Kd[e]);
+        EEPROM_WRITE_VAR(i,PID_PARAM(Kd,e));
         #ifdef PID_ADD_EXTRUSION_RATE
-        EEPROM_WRITE_VAR(i,Kc[e]);
+        EEPROM_WRITE_VAR(i,PID_PARAM(Kc,e));
         #else//PID_ADD_EXTRUSION_RATE
 		dummy = 1.0f; // 1.0 = default kc
 	    EEPROM_WRITE_VAR(dummmy);
@@ -232,9 +232,9 @@ SERIAL_ECHOLNPGM("Scaling factors:");
     SERIAL_ECHO_START;
     SERIAL_ECHOLNPGM("PID settings:");
 	SERIAL_ECHO_START;
-    SERIAL_ECHOPAIR("   M301 P", Kp[0]); // for compatibility with hosts, only echos values for E0
+    SERIAL_ECHOPAIR("   M301 P", PID_PARAM(Kp,0)); // for compatibility with hosts, only echos values for E0
-    SERIAL_ECHOPAIR(" I" ,unscalePID_i(Ki[0])); 
+	SERIAL_ECHOPAIR(" I", unscalePID_i(PID_PARAM(Ki, 0)));
-    SERIAL_ECHOPAIR(" D" ,unscalePID_d(Kd[0]));  
+	SERIAL_ECHOPAIR(" D", unscalePID_d(PID_PARAM(Kd, 0)));
     SERIAL_ECHOLN(""); 
 #endif//PIDTEMP
 #ifdef FWRETRACT
@@ -341,11 +341,11 @@ void Config_RetrieveSettings()
 		  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,PID_PARAM(Kp,e));
-            EEPROM_READ_VAR(i,Ki[e]);
+            EEPROM_READ_VAR(i,PID_PARAM(Ki,e));
-		    EEPROM_READ_VAR(i,Kd[e]);
+		    EEPROM_READ_VAR(i,PID_PARAM(Kd,e));
 #ifdef PID_ADD_EXTRUSION_RATE
-            EEPROM_READ_VAR(i,Kc[e]);
+            EEPROM_READ_VAR(i,PID_PARAM(Kc,e));
 #else//PID_ADD_EXTRUSION_RATE
 	        EEPROM_READ_VAR(i,dummy);
 #endif//PID_ADD_EXTRUSION_RATE
@@ -470,13 +470,17 @@ void Config_ResetDefault()
     lcd_contrast = DEFAULT_LCD_CONTRAST;
 #endif//DOGLCD
 #ifdef PIDTEMP
+#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
 	{
-      Kp[e] = DEFAULT_Kp;
+      PID_PARAM(Kp,e) = DEFAULT_Kp;
-      Ki[e] = scalePID_i(DEFAULT_Ki);
+      PID_PARAM(Ki,e) = scalePID_i(DEFAULT_Ki);
-      Kd[e] = scalePID_d(DEFAULT_Kd);
+      PID_PARAM(Kd,e) = scalePID_d(DEFAULT_Kd);
       #ifdef PID_ADD_EXTRUSION_RATE
-      Kc[e] = DEFAULT_Kc;
+        PID_PARAM(Kc,e) = DEFAULT_Kc;
       #endif//PID_ADD_EXTRUSION_RATE
     }
     // call updatePID (similar to when we have processed M301)

Marlin/Marlin_main.cpp

@@ -3209,27 +3209,29 @@ Sigma_Exit:
 		if (e < EXTRUDERS) // catch bad input value
 		{
 
-			if (code_seen('P')) Kp[e] = code_value();
+			if (code_seen('P')) PID_PARAM(Kp,e) = code_value();
-			if (code_seen('I')) Ki[e] = scalePID_i(code_value());
+			if (code_seen('I')) PID_PARAM(Ki,e) = scalePID_i(code_value());
-			if (code_seen('D')) Kd[e] = scalePID_d(code_value());
+			if (code_seen('D')) PID_PARAM(Kd,e) = scalePID_d(code_value());
 			#ifdef PID_ADD_EXTRUSION_RATE
-			if (code_seen('C')) Kc[e] = code_value();
+			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(Kp[e]);
+			SERIAL_PROTOCOL(PID_PARAM(Kp,e));
 			SERIAL_PROTOCOL(" i:");
-			SERIAL_PROTOCOL(unscalePID_i(Ki[e]));
+			SERIAL_PROTOCOL(unscalePID_i(PID_PARAM(Ki,e)));
 			SERIAL_PROTOCOL(" d:");
-			SERIAL_PROTOCOL(unscalePID_d(Kd[e]));
+			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(Kc[e]);
+			SERIAL_PROTOCOL(PID_PARAM(Kc,e));
 			#endif
 			SERIAL_PROTOCOLLN("");
 		

Marlin/temperature.cpp

@@ -126,12 +126,21 @@ static volatile bool temp_meas_ready = false;
 #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
+  #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
@@ -343,7 +352,7 @@ void updatePID()
 {
 #ifdef PIDTEMP
   for(int e = 0; e < EXTRUDERS; e++) { 
-     temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / Ki[e];  
+     temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / PID_PARAM(Ki,e);  
   }
 #endif
 #ifdef PIDTEMPBED
@@ -464,14 +473,14 @@ void manage_heater()
             temp_iState[e] = 0.0;
             pid_reset[e] = false;
           }
-          pTerm[e] = Kp[e] * 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[e] * 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[e] * (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
@@ -811,7 +820,7 @@ void tp_init()
     maxttemp[e] = maxttemp[0];
 #ifdef PIDTEMP
     temp_iState_min[e] = 0.0;
-    temp_iState_max[e] = PID_INTEGRAL_DRIVE_MAX / Ki[e];
+    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

@@ -58,7 +58,14 @@ extern float current_temperature_bed;
 #endif
 
 #ifdef PIDTEMP
-  extern float Kp[EXTRUDERS], Ki[EXTRUDERS], Kd[EXTRUDERS], Kc[EXTRUDERS];
+
+  #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

@@ -790,41 +790,43 @@ static void lcd_control_temperature_menu()
 #ifdef PIDTEMP
 	// set up temp variables - undo the default scaling
 	pid_current_extruder = 0;
-	raw_Ki = unscalePID_i(Ki[0]);
+	raw_Ki = unscalePID_i(PID_PARAM(Ki,0));
-	raw_Kd = unscalePID_d(Kd[0]);
+	raw_Kd = unscalePID_d(PID_PARAM(Kd,0));
-	MENU_ITEM_EDIT(float52, MSG_PID_P, &Kp[0], 1, 9990);
+	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, &Kc[0], 1, 9990);
+	  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 = 1;
+	  pid_current_extruder = 0;
-	raw_Ki = unscalePID_i(Ki[1]);
+	  raw_Ki = unscalePID_i(PID_PARAM(Ki,1));
-	raw_Kd = unscalePID_d(Kd[1]);
+	  raw_Kd = unscalePID_d(PID_PARAM(Kd,1));
-	MENU_ITEM_EDIT(float52, MSG_PID_P1, &Kp[1], 1, 9990);
+	  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, &Kc[1], 1, 9990);
+	    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 = 2;
+	    pid_current_extruder = 0;
-	raw_Ki = unscalePID_i(Ki[2]);
+	    raw_Ki = unscalePID_i(PID_PARAM(Ki,2));
-	raw_Kd = unscalePID_d(Kd[2]);
+	    raw_Kd = unscalePID_d(PID_PARAM(Kd,2));
-	MENU_ITEM_EDIT(float52, MSG_PID_P2, &Kp[2], 1, 9990);
+	    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, &Kc[2], 1, 9990);
+	      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);
@@ -1731,7 +1733,7 @@ char *ftostr52(const float &x)
 void copy_and_scalePID_i()
 {
 #ifdef PIDTEMP
-  Ki[pid_current_extruder] = scalePID_i(raw_Ki);
+  PID_PARAM(Ki, pid_current_extruder) = scalePID_i(raw_Ki);
   updatePID();
 #endif
 }
@@ -1741,7 +1743,7 @@ void copy_and_scalePID_i()
 void copy_and_scalePID_d()
 {
 #ifdef PIDTEMP
-  Kd[pid_current_extruder] = scalePID_d(raw_Kd);
+	PID_PARAM(Kd, pid_current_extruder) = scalePID_d(raw_Kd);
   updatePID();
 #endif
 }