Per-Hotend Default PIDs (#18483)

Marlin/src/gcode/config/M301.cpp

 /**
  * M301: Set PID parameters P I D (and optionally C, L)
  *
+ *   E[extruder] Default: 0
+ *
  *   P[float] Kp term
  *   I[float] Ki term (unscaled)
  *   D[float] Kd term (unscaled)
     #endif
 
     thermalManager.updatePID();
+
     SERIAL_ECHO_START();
     #if ENABLED(PID_PARAMS_PER_HOTEND)
       SERIAL_ECHOPAIR(" e:", e); // specify extruder in serial output

Marlin/src/inc/Conditionals_LCD.h

     #define HAS_MULTI_HOTEND 1
     #define HAS_HOTEND_OFFSET 1
   #endif
+#else
+  #undef PID_PARAMS_PER_HOTEND
 #endif
 
 // Helper macros for extruder and hotend arrays

Marlin/src/inc/SanityCheck.h

 #endif
 
 /**
- * Test Heater, Temp Sensor, and Extruder Pins; Sensor Type must also be set.
+ * A Sensor ID has to be set for each heater
  */
-#if !HAS_HEATER_0
-  #error "HEATER_0_PIN not defined for this board."
-#elif !ANY_PIN(TEMP_0, MAX6675_SS)
-  #error "TEMP_0_PIN not defined for this board."
-#elif ((defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)) && !PINS_EXIST(E0_STEP, E0_DIR))
-  #error "E0_STEP_PIN or E0_DIR_PIN not defined for this board."
-#elif ( !(defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)) && (!PINS_EXIST(E0_STEP, E0_DIR) || !HAS_E0_ENABLE))
-  #error "E0_STEP_PIN, E0_DIR_PIN, or E0_ENABLE_PIN not defined for this board."
-#elif EXTRUDERS && TEMP_SENSOR_0 == 0
-  #error "TEMP_SENSOR_0 is required with any extruders."
-#endif
-
-// Pins are required for heaters
-#if ENABLED(HEATER_0_USES_MAX6675) && !PIN_EXISTS(MAX6675_SS)
-  #error "MAX6675_SS_PIN (required for TEMP_SENSOR_0) not defined for this board."
-#elif HAS_HOTEND && !HAS_TEMP_HOTEND
-  #error "TEMP_0_PIN (required for TEMP_SENSOR_0) not defined for this board."
-#elif EITHER(HAS_MULTI_HOTEND, HEATERS_PARALLEL) && !HAS_HEATER_1
-  #error "HEATER_1_PIN not defined for this board."
-#endif
 
 #if HAS_MULTI_HOTEND
   #if ENABLED(HEATER_1_USES_MAX6675) && !PIN_EXISTS(MAX6675_SS2)
 #endif
 
 /**
+ * Test Heater, Temp Sensor, and Extruder Pins
+ */
+#if !HAS_HEATER_0
+  #error "HEATER_0_PIN not defined for this board."
+#elif !ANY_PIN(TEMP_0, MAX6675_SS)
+  #error "TEMP_0_PIN not defined for this board."
+#elif ((defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)) && !PINS_EXIST(E0_STEP, E0_DIR))
+  #error "E0_STEP_PIN or E0_DIR_PIN not defined for this board."
+#elif ( !(defined(__AVR_ATmega644P__) || defined(__AVR_ATmega1284P__)) && (!PINS_EXIST(E0_STEP, E0_DIR) || !HAS_E0_ENABLE))
+  #error "E0_STEP_PIN, E0_DIR_PIN, or E0_ENABLE_PIN not defined for this board."
+#elif EXTRUDERS && TEMP_SENSOR_0 == 0
+  #error "TEMP_SENSOR_0 is required if there are any extruders."
+#endif
+
+// Pins are required for heaters
+#if ENABLED(HEATER_0_USES_MAX6675) && !PIN_EXISTS(MAX6675_SS)
+  #error "MAX6675_SS_PIN (required for TEMP_SENSOR_0) not defined for this board."
+#elif HAS_HOTEND && !HAS_TEMP_HOTEND
+  #error "TEMP_0_PIN (required for TEMP_SENSOR_0) not defined for this board."
+#elif EITHER(HAS_MULTI_HOTEND, HEATERS_PARALLEL) && !HAS_HEATER_1
+  #error "HEATER_1_PIN is not defined. TEMP_SENSOR_1 might not be set, or the board (not EEB / EEF?) doesn't define a pin."
+#endif
+
+/**
  * Temperature status LEDs
  */
 #if ENABLED(TEMP_STAT_LEDS) && !ANY_PIN(STAT_LED_RED, STAT_LED_BLUE)

Marlin/src/lcd/menu/menu_advanced.cpp

   // Helpers for editing PID Ki & Kd values
   // grab the PID value out of the temp variable; scale it; then update the PID driver
   void copy_and_scalePID_i(int16_t e) {
-    #if DISABLED(PID_PARAMS_PER_HOTEND) || HOTENDS == 1
-      UNUSED(e);
-    #endif
+    TERN(PID_PARAMS_PER_HOTEND,,UNUSED(e));
     PID_PARAM(Ki, e) = scalePID_i(raw_Ki);
     thermalManager.updatePID();
   }
   void copy_and_scalePID_d(int16_t e) {
-    #if DISABLED(PID_PARAMS_PER_HOTEND) || HOTENDS == 1
-      UNUSED(e);
-    #endif
+    TERN(PID_PARAMS_PER_HOTEND,,UNUSED(e));
     PID_PARAM(Kd, e) = scalePID_d(raw_Kd);
     thermalManager.updatePID();
   }
 
 #if HAS_HOTEND
   DEFINE_PIDTEMP_FUNCS(0);
-  #if BOTH(HAS_MULTI_HOTEND, PID_PARAMS_PER_HOTEND)
+  #if ENABLED(PID_PARAMS_PER_HOTEND)
     REPEAT_S(1, HOTENDS, DEFINE_PIDTEMP_FUNCS)
   #endif
 #endif
     #endif
 
     PID_EDIT_MENU_ITEMS(0);
-    #if BOTH(HAS_MULTI_HOTEND, PID_PARAMS_PER_HOTEND)
+    #if ENABLED(PID_PARAMS_PER_HOTEND)
       REPEAT_S(1, HOTENDS, PID_EDIT_MENU_ITEMS)
     #endif
 

Marlin/src/module/configuration_store.cpp

   //
 
   #if ENABLED(PIDTEMP)
+    #if ENABLED(PID_PARAMS_PER_HOTEND)
+      constexpr float defKp[] =
+        #ifdef DEFAULT_Kp_LIST
+          DEFAULT_Kp_LIST
+        #else
+          ARRAY_BY_HOTENDS1(DEFAULT_Kp)
+        #endif
+      , defKi[] =
+        #ifdef DEFAULT_Ki_LIST
+          DEFAULT_Ki_LIST
+        #else
+          ARRAY_BY_HOTENDS1(DEFAULT_Ki)
+        #endif
+      , defKd[] =
+        #ifdef DEFAULT_Kd_LIST
+          DEFAULT_Kd_LIST
+        #else
+          ARRAY_BY_HOTENDS1(DEFAULT_Kd)
+        #endif
+      ;
+      static_assert(WITHIN(COUNT(defKp), 1, HOTENDS), "DEFAULT_Kp_LIST must have between 1 and HOTENDS items.");
+      static_assert(WITHIN(COUNT(defKi), 1, HOTENDS), "DEFAULT_Ki_LIST must have between 1 and HOTENDS items.");
+      static_assert(WITHIN(COUNT(defKd), 1, HOTENDS), "DEFAULT_Kd_LIST must have between 1 and HOTENDS items.");
+      #if ENABLED(PID_EXTRUSION_SCALING)
+        constexpr float defKc[] =
+          #ifdef DEFAULT_Kc_LIST
+            DEFAULT_Kc_LIST
+          #else
+            ARRAY_BY_HOTENDS1(DEFAULT_Kc)
+          #endif
+        ;
+        static_assert(WITHIN(COUNT(defKc), 1, HOTENDS), "DEFAULT_Kc_LIST must have between 1 and HOTENDS items.");
+      #endif
+      #if ENABLED(PID_FAN_SCALING)
+        constexpr float defKf[] =
+          #ifdef DEFAULT_Kf_LIST
+            DEFAULT_Kf_LIST
+          #else
+            ARRAY_BY_HOTENDS1(DEFAULT_Kf)
+          #endif
+        ;
+        static_assert(WITHIN(COUNT(defKf), 1, HOTENDS), "DEFAULT_Kf_LIST must have between 1 and HOTENDS items.");
+      #endif
+      #define PID_DEFAULT(N,E) def##N[E]
+    #else
+      #define PID_DEFAULT(N,E) DEFAULT_##N
+    #endif
     HOTEND_LOOP() {
-      PID_PARAM(Kp, e) = float(DEFAULT_Kp);
-      PID_PARAM(Ki, e) = scalePID_i(DEFAULT_Ki);
-      PID_PARAM(Kd, e) = scalePID_d(DEFAULT_Kd);
-      TERN_(PID_EXTRUSION_SCALING, PID_PARAM(Kc, e) = DEFAULT_Kc);
-      TERN_(PID_FAN_SCALING, PID_PARAM(Kf, e) = DEFAULT_Kf);
+      PID_PARAM(Kp, e) = float(PID_DEFAULT(Kp, ALIM(e, defKp)));
+      PID_PARAM(Ki, e) = scalePID_i(PID_DEFAULT(Ki, ALIM(e, defKi)));
+      PID_PARAM(Kd, e) = scalePID_d(PID_DEFAULT(Kd, ALIM(e, defKd)));
+      TERN_(PID_EXTRUSION_SCALING, PID_PARAM(Kc, e) = float(PID_DEFAULT(Kc, ALIM(e, defKc))));
+      TERN_(PID_FAN_SCALING, PID_PARAM(Kf, e) = float(PID_DEFAULT(Kf, ALIM(e, defKf))));
     }
   #endif
 
         HOTEND_LOOP() {
           CONFIG_ECHO_START();
           SERIAL_ECHOPAIR_P(
-            #if BOTH(HAS_MULTI_HOTEND, PID_PARAMS_PER_HOTEND)
+            #if ENABLED(PID_PARAMS_PER_HOTEND)
               PSTR("  M301 E"), e,
               SP_P_STR
             #else

Marlin/src/module/temperature.h

   #define SOFT_PWM_SCALE 0
 #endif
 
-#if HOTENDS <= 1
-  #define HOTEND_INDEX  0
-  #define E_NAME
-#else
-  #define HOTEND_INDEX  e
-  #define E_NAME e
-#endif
+#define HOTEND_INDEX TERN(HAS_MULTI_HOTEND, e, 0)
+#define E_NAME TERN_(HAS_MULTI_HOTEND, e)
 
 // Identifiers for other heaters
 typedef enum : int8_t {
   typedef IF<(LPQ_MAX_LEN > 255), uint16_t, uint8_t>::type lpq_ptr_t;
 #endif
 
+#define PID_PARAM(F,H) _PID_##F(TERN(PID_PARAMS_PER_HOTEND, H, 0))
+#define _PID_Kp(H) TERN(PIDTEMP, Temperature::temp_hotend[H].pid.Kp, NAN)
+#define _PID_Ki(H) TERN(PIDTEMP, Temperature::temp_hotend[H].pid.Ki, NAN)
+#define _PID_Kd(H) TERN(PIDTEMP, Temperature::temp_hotend[H].pid.Kd, NAN)
 #if ENABLED(PIDTEMP)
-  #define _PID_Kp(H) Temperature::temp_hotend[H].pid.Kp
-  #define _PID_Ki(H) Temperature::temp_hotend[H].pid.Ki
-  #define _PID_Kd(H) Temperature::temp_hotend[H].pid.Kd
-  #if ENABLED(PID_EXTRUSION_SCALING)
-    #define _PID_Kc(H) Temperature::temp_hotend[H].pid.Kc
-  #else
-    #define _PID_Kc(H) 1
-  #endif
-
-  #if ENABLED(PID_FAN_SCALING)
-    #define _PID_Kf(H) Temperature::temp_hotend[H].pid.Kf
-  #else
-    #define _PID_Kf(H) 0
-  #endif
+  #define _PID_Kc(H) TERN(PID_EXTRUSION_SCALING, Temperature::temp_hotend[H].pid.Kc, 1)
+  #define _PID_Kf(H) TERN(PID_FAN_SCALING,       Temperature::temp_hotend[H].pid.Kf, 0)
 #else
-  #define _PID_Kp(H) NAN
-  #define _PID_Ki(H) NAN
-  #define _PID_Kd(H) NAN
   #define _PID_Kc(H) 1
+  #define _PID_Kf(H) 0
 #endif
 
-#define PID_PARAM(F,H) _PID_##F(H)
-
 /**
  * States for ADC reading in the ISR
  */