✨ Controllerfan PWM scaling, kickstart (#24873)

Marlin/Configuration_adv.h

   #endif
 #endif
 
-// When first starting the main fan, run it at full speed for the
-// given number of milliseconds.  This gets the fan spinning reliably
-// before setting a PWM value. (Does not work with software PWM for fan on Sanguinololu)
-//#define FAN_KICKSTART_TIME 100
+/**
+ * Fan Kickstart
+ * When part cooling or controller fans first start, run at a speed that
+ * gets it spinning reliably for a short time before setting the requested speed.
+ * (Does not work on Sanguinololu with FAN_SOFT_PWM.)
+ */
+//#define FAN_KICKSTART_TIME  100  // (ms)
+//#define FAN_KICKSTART_POWER 180  // 64-255
 
 // Some coolers may require a non-zero "off" state.
 //#define FAN_OFF_PWM  1

Marlin/src/feature/controllerfan.cpp

       ? settings.active_speed : settings.idle_speed
     );
 
+    speed = CALC_FAN_SPEED(speed);
+
+    #if FAN_KICKSTART_TIME
+      static millis_t fan_kick_end = 0;
+      if (speed > FAN_OFF_PWM) {
+        if (!fan_kick_end) {
+          fan_kick_end = ms + FAN_KICKSTART_TIME; // May be longer based on slow update interval for controller fn check. Sets minimum
+          speed = FAN_KICKSTART_POWER;
+        }
+        else if (PENDING(ms, fan_kick_end))
+          speed = FAN_KICKSTART_POWER;
+      }
+      else
+        fan_kick_end = 0;
+    #endif
+
     #if ENABLED(FAN_SOFT_PWM)
       thermalManager.soft_pwm_controller_speed = speed;
     #else

Marlin/src/inc/Conditionals_adv.h

 #if ANY(DISABLE_INACTIVE_X, DISABLE_INACTIVE_Y, DISABLE_INACTIVE_Z, DISABLE_INACTIVE_I, DISABLE_INACTIVE_J, DISABLE_INACTIVE_K, DISABLE_INACTIVE_U, DISABLE_INACTIVE_V, DISABLE_INACTIVE_W, DISABLE_INACTIVE_E)
   #define HAS_DISABLE_INACTIVE_AXIS 1
 #endif
+
+// Fan Kickstart
+#if FAN_KICKSTART_TIME && !defined(FAN_KICKSTART_POWER)
+  #define FAN_KICKSTART_POWER 180
+#endif
+
+#if FAN_MIN_PWM == 0 && FAN_MAX_PWM == 255
+  #define CALC_FAN_SPEED(f) (f ?: FAN_OFF_PWM)
+#else
+  #define CALC_FAN_SPEED(f) (f ? map(f, 1, 255, FAN_MIN_PWM, FAN_MAX_PWM) : FAN_OFF_PWM)
+#endif

Marlin/src/inc/SanityCheck.h

   #error "To use BED_LIMIT_SWITCHING you must disable PIDTEMPBED."
 #endif
 
+// Fan Kickstart
+#if FAN_KICKSTART_TIME && defined(FAN_KICKSTART_POWER) && !WITHIN(FAN_KICKSTART_POWER, 64, 255)
+  #error "FAN_KICKSTART_POWER must be an integer from 64 to 255."
+#endif
+
 /**
  * Synchronous M106/M107 checks
  */

Marlin/src/module/planner.cpp

 
   void Planner::sync_fan_speeds(uint8_t (&fan_speed)[FAN_COUNT]) {
 
-    #if FAN_MIN_PWM != 0 || FAN_MAX_PWM != 255
-      #define CALC_FAN_SPEED(f) (fan_speed[f] ? map(fan_speed[f], 1, 255, FAN_MIN_PWM, FAN_MAX_PWM) : FAN_OFF_PWM)
-    #else
-      #define CALC_FAN_SPEED(f) (fan_speed[f] ?: FAN_OFF_PWM)
-    #endif
-
     #if ENABLED(FAN_SOFT_PWM)
-      #define _FAN_SET(F) thermalManager.soft_pwm_amount_fan[F] = CALC_FAN_SPEED(F);
+      #define _FAN_SET(F) thermalManager.soft_pwm_amount_fan[F] = CALC_FAN_SPEED(fan_speed[F]);
     #else
-      #define _FAN_SET(F) hal.set_pwm_duty(pin_t(FAN##F##_PIN), CALC_FAN_SPEED(F));
+      #define _FAN_SET(F) hal.set_pwm_duty(pin_t(FAN##F##_PIN), CALC_FAN_SPEED(fan_speed[F]));
     #endif
     #define FAN_SET(F) do{ kickstart_fan(fan_speed, ms, F); _FAN_SET(F); }while(0)
 
 
     void Planner::kickstart_fan(uint8_t (&fan_speed)[FAN_COUNT], const millis_t &ms, const uint8_t f) {
       static millis_t fan_kick_end[FAN_COUNT] = { 0 };
-      if (fan_speed[f]) {
+      if (fan_speed[f] > FAN_OFF_PWM) {
         if (fan_kick_end[f] == 0) {
           fan_kick_end[f] = ms + FAN_KICKSTART_TIME;
-          fan_speed[f] = 255;
+          fan_speed[f] = FAN_KICKSTART_POWER;
         }
         else if (PENDING(ms, fan_kick_end[f]))
-          fan_speed[f] = 255;
+          fan_speed[f] = FAN_KICKSTART_POWER;
       }
       else
         fan_kick_end[f] = 0;

Marlin/src/module/temperature.cpp

 #endif
 
 #if EITHER(AUTO_POWER_E_FANS, HAS_FANCHECK)
-  uint8_t Temperature::autofan_speed[HOTENDS]; // = { 0 }
+  uint8_t Temperature::autofan_speed[HOTENDS] = ARRAY_N_1(HOTENDS, FAN_OFF_PWM);
 #endif
 
 #if ENABLED(AUTO_POWER_CHAMBER_FAN)
-  uint8_t Temperature::chamberfan_speed; // = 0
+  uint8_t Temperature::chamberfan_speed = FAN_OFF_PWM;
 #endif
 
 #if ENABLED(AUTO_POWER_COOLER_FAN)
-  uint8_t Temperature::coolerfan_speed; // = 0
+  uint8_t Temperature::coolerfan_speed = FAN_OFF_PWM;
 #endif
 
 #if BOTH(FAN_SOFT_PWM, USE_CONTROLLER_FAN)
-  uint8_t Temperature::soft_pwm_controller_speed;
+  uint8_t Temperature::soft_pwm_controller_speed = FAN_OFF_PWM;
 #endif
 
 // Init fans according to whether they're native PWM or Software PWM
 // HAS_FAN does not include CONTROLLER_FAN
 #if HAS_FAN
 
-  uint8_t Temperature::fan_speed[FAN_COUNT]; // = { 0 }
+  uint8_t Temperature::fan_speed[FAN_COUNT] = ARRAY_N_1(FAN_COUNT, FAN_OFF_PWM);
 
   #if ENABLED(EXTRA_FAN_SPEED)
 
-    Temperature::extra_fan_t Temperature::extra_fan_speed[FAN_COUNT];
+    Temperature::extra_fan_t Temperature::extra_fan_speed[FAN_COUNT] = ARRAY_N_1(FAN_COUNT, FAN_OFF_PWM);
 
     /**
      * Handle the M106 P<fan> T<speed> command:
 
   #if EITHER(PROBING_FANS_OFF, ADVANCED_PAUSE_FANS_PAUSE)
     bool Temperature::fans_paused; // = false;
-    uint8_t Temperature::saved_fan_speed[FAN_COUNT]; // = { 0 }
+    uint8_t Temperature::saved_fan_speed[FAN_COUNT] = ARRAY_N_1(FAN_COUNT, FAN_OFF_PWM);
   #endif
 
   #if ENABLED(ADAPTIVE_FAN_SLOWING)

Marlin/src/module/tool_change.cpp

     #if HAS_FAN && TOOLCHANGE_FS_FAN >= 0
       thermalManager.fan_speed[TOOLCHANGE_FS_FAN] = toolchange_settings.fan_speed;
       gcode.dwell(SEC_TO_MS(toolchange_settings.fan_time));
-      thermalManager.fan_speed[TOOLCHANGE_FS_FAN] = 0;
+      thermalManager.fan_speed[TOOLCHANGE_FS_FAN] = FAN_OFF_PWM;
     #endif
   }