Support for multiple PWM fans

Marlin/Conditionals.h

@@ -465,7 +465,9 @@
   #define HAS_AUTO_FAN_2 (PIN_EXISTS(EXTRUDER_2_AUTO_FAN))
   #define HAS_AUTO_FAN_3 (PIN_EXISTS(EXTRUDER_3_AUTO_FAN))
   #define HAS_AUTO_FAN (HAS_AUTO_FAN_0 || HAS_AUTO_FAN_1 || HAS_AUTO_FAN_2 || HAS_AUTO_FAN_3)
-  #define HAS_FAN (PIN_EXISTS(FAN))
+  #define HAS_FAN0 (PIN_EXISTS(FAN))
+  #define HAS_FAN1 (PIN_EXISTS(FAN1) && CONTROLLERFAN_PIN != FAN1_PIN && EXTRUDER_0_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_1_AUTO_FAN_PIN != FAN1_PIN && EXTRUDER_2_AUTO_FAN_PIN != FAN1_PIN)
+  #define HAS_FAN2 (PIN_EXISTS(FAN2) && CONTROLLERFAN_PIN != FAN2_PIN && EXTRUDER_0_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_1_AUTO_FAN_PIN != FAN2_PIN && EXTRUDER_2_AUTO_FAN_PIN != FAN2_PIN)
   #define HAS_CONTROLLERFAN (PIN_EXISTS(CONTROLLERFAN))
   #define HAS_SERVOS (defined(NUM_SERVOS) && NUM_SERVOS > 0)
   #define HAS_SERVO_0 (PIN_EXISTS(SERVO0))
@@ -550,10 +552,32 @@
   #if HAS_HEATER_BED
     #define WRITE_HEATER_BED(v) WRITE(HEATER_BED_PIN, v)
   #endif
-  #if HAS_FAN
+
-    #define WRITE_FAN(v) WRITE(FAN_PIN, v)
+  /**
+   * Up to 3 PWM fans
+   */
+  #if HAS_FAN2
+    #define FAN_COUNT 3
+  #elif HAS_FAN1
+    #define FAN_COUNT 2
+  #elif HAS_FAN0
+    #define FAN_COUNT 1
+  #else
+    #define FAN_COUNT 0
   #endif
 
+  #if HAS_FAN0
+    #define WRITE_FAN(v) WRITE(FAN_PIN, v)
+    #define WRITE_FAN0(v) WRITE_FAN(v)
+  #endif
+  #if HAS_FAN1
+    #define WRITE_FAN1(v) WRITE(FAN1_PIN, v)
+  #endif
+  #if HAS_FAN2
+    #define WRITE_FAN2(v) WRITE(FAN2_PIN, v)
+  #endif
+  #define WRITE_FAN_N(n, v) WRITE_FAN##n(v)
+
   #define HAS_BUZZER (PIN_EXISTS(BEEPER) || defined(LCD_USE_I2C_BUZZER))
 
   #if defined(NUM_SERVOS) && NUM_SERVOS > 0

Marlin/Marlin.h

@@ -306,17 +306,15 @@ extern bool axis_homed[3]; // axis[n].is_homed
   extern float extrude_min_temp;
 #endif
 
-extern int fanSpeed;
+#if FAN_COUNT > 0
+  extern int fanSpeeds[FAN_COUNT];
+#endif
 
 #if ENABLED(BARICUDA)
   extern int ValvePressure;
   extern int EtoPPressure;
 #endif
 
-#if ENABLED(FAN_SOFT_PWM)
-  extern unsigned char fanSpeedSoftPwm;
-#endif
-
 #if ENABLED(FILAMENT_SENSOR)
   extern float filament_width_nominal;  //holds the theoretical filament diameter i.e., 3.00 or 1.75
   extern bool filament_sensor;  //indicates that filament sensor readings should control extrusion

Marlin/Marlin_main.cpp

@@ -267,8 +267,11 @@ float home_offset[3] = { 0 };
 float min_pos[3] = { X_MIN_POS, Y_MIN_POS, Z_MIN_POS };
 float max_pos[3] = { X_MAX_POS, Y_MAX_POS, Z_MAX_POS };
 
+#if FAN_COUNT > 0
+  int fanSpeeds[FAN_COUNT] = { 0 };
+#endif
+
 uint8_t active_extruder = 0;
-int fanSpeed = 0;
 bool cancel_heatup = false;
 
 const char errormagic[] PROGMEM = "Error:";
@@ -3597,8 +3600,16 @@ inline void gcode_M42() {
       }
     }
 
-    #if HAS_FAN
+    #if HAS_FAN0
-      if (pin_number == FAN_PIN) fanSpeed = pin_status;
+      if (pin_number == FAN_PIN)  fanSpeeds[0] = pin_status;
+    #endif
+
+    #if HAS_FAN1
+      if (pin_number == FAN1_PIN) fanSpeeds[1] = pin_status;
+    #endif
+
+    #if HAS_FAN2
+      if (pin_number == FAN2_PIN) fanSpeeds[2] = pin_status;
     #endif
 
     if (pin_number > -1) {
@@ -3968,19 +3979,30 @@ inline void gcode_M105() {
   SERIAL_EOL;
 }
 
-#if HAS_FAN
+#if FAN_COUNT > 0
 
   /**
    * M106: Set Fan Speed
+   *
+   *  S<int>   Speed between 0-255
+   *  P<index> Fan index, if more than one fan
    */
-  inline void gcode_M106() { fanSpeed = code_seen('S') ? constrain(code_value_short(), 0, 255) : 255; }
+  inline void gcode_M106() {
+    uint16_t s = code_seen('S') ? code_value_short() : 255,
+             p = code_seen('P') ? code_value_short() : 0;
+    NOMORE(s, 255);
+    if (p < FAN_COUNT) fanSpeeds[p] = s;
+  }
 
   /**
    * M107: Fan Off
    */
-  inline void gcode_M107() { fanSpeed = 0; }
+  inline void gcode_M107() {
+    uint16_t p = code_seen('P') ? code_value_short() : 0;
+    if (p < FAN_COUNT) fanSpeeds[p] = 0;
+  }
 
-#endif // HAS_FAN
+#endif // FAN_COUNT > 0
 
 /**
  * M109: Sxxx Wait for extruder(s) to reach temperature. Waits only when heating.
@@ -4261,7 +4283,13 @@ inline void gcode_M140() {
 inline void gcode_M81() {
   disable_all_heaters();
   finishAndDisableSteppers();
-  fanSpeed = 0;
+  #if FAN_COUNT > 0
+    #if FAN_COUNT > 1
+      for (uint8_t i = 0; i < FAN_COUNT; i++) fanSpeeds[i] = 0;
+    #else
+      fanSpeeds[0] = 0;
+    #endif
+  #endif
   delay(1000); // Wait 1 second before switching off
   #if HAS_SUICIDE
     st_synchronize();
@@ -6015,14 +6043,14 @@ void process_next_command() {
           break;
       #endif // HAS_TEMP_BED
 
-      #if HAS_FAN
+      #if FAN_COUNT > 0
         case 106: // M106: Fan On
           gcode_M106();
           break;
         case 107: // M107: Fan Off
           gcode_M107();
           break;
-      #endif // HAS_FAN
+      #endif // FAN_COUNT > 0
 
       #if ENABLED(BARICUDA)
         // PWM for HEATER_1_PIN

Marlin/SanityCheck.h

@@ -264,7 +264,8 @@
 /**
  * Make sure auto fan pins don't conflict with the fan pin
  */
-#if HAS_AUTO_FAN && HAS_FAN
+#if HAS_AUTO_FAN
+  #if HAS_FAN0
     #if EXTRUDER_0_AUTO_FAN_PIN == FAN_PIN
       #error You cannot set EXTRUDER_0_AUTO_FAN_PIN equal to FAN_PIN.
     #elif EXTRUDER_1_AUTO_FAN_PIN == FAN_PIN
@@ -274,12 +275,25 @@
     #elif EXTRUDER_3_AUTO_FAN_PIN == FAN_PIN
       #error You cannot set EXTRUDER_3_AUTO_FAN_PIN equal to FAN_PIN.
     #endif
+  #endif
 #endif
 
-#if HAS_FAN && CONTROLLERFAN_PIN == FAN_PIN
+#if HAS_FAN0 && CONTROLLERFAN_PIN == FAN_PIN
   #error You cannot set CONTROLLERFAN_PIN equal to FAN_PIN.
 #endif
 
+#if HAS_CONTROLLERFAN
+  #if EXTRUDER_0_AUTO_FAN_PIN == CONTROLLERFAN_PIN
+    #error You cannot set EXTRUDER_0_AUTO_FAN_PIN equal to CONTROLLERFAN_PIN.
+  #elif EXTRUDER_1_AUTO_FAN_PIN == CONTROLLERFAN_PIN
+    #error You cannot set EXTRUDER_1_AUTO_FAN_PIN equal to CONTROLLERFAN_PIN.
+  #elif EXTRUDER_2_AUTO_FAN_PIN == CONTROLLERFAN_PIN
+    #error You cannot set EXTRUDER_2_AUTO_FAN_PIN equal to CONTROLLERFAN_PIN.
+  #elif EXTRUDER_3_AUTO_FAN_PIN == CONTROLLERFAN_PIN
+    #error You cannot set EXTRUDER_3_AUTO_FAN_PIN equal to CONTROLLERFAN_PIN.
+  #endif
+#endif
+
 /**
  * Test Heater, Temp Sensor, and Extruder Pins; Sensor Type must also be set.
  */

Marlin/dogm_lcd_implementation.h

@@ -283,7 +283,7 @@ static void lcd_implementation_status_screen() {
   u8g.setColorIndex(1); // black on white
 
   // Symbols menu graphics, animated fan
-  u8g.drawBitmapP(9,1,STATUS_SCREENBYTEWIDTH,STATUS_SCREENHEIGHT, (blink % 2) && fanSpeed ? status_screen0_bmp : status_screen1_bmp);
+  u8g.drawBitmapP(9,1,STATUS_SCREENBYTEWIDTH,STATUS_SCREENHEIGHT, (blink % 2) && fanSpeeds[0] ? status_screen0_bmp : status_screen1_bmp);
 
   #if ENABLED(SDSUPPORT)
     // SD Card Symbol
@@ -324,8 +324,8 @@ static void lcd_implementation_status_screen() {
   // Fan
   lcd_setFont(FONT_STATUSMENU);
   u8g.setPrintPos(104, 27);
-  #if HAS_FAN
+  #if HAS_FAN0
-    int per = ((fanSpeed + 1) * 100) / 256;
+    int per = ((fanSpeeds[0] + 1) * 100) / 256;
     if (per) {
       lcd_print(itostr3(per));
       lcd_print('%');

Marlin/pins_MEGACONTROLLER.h

@@ -49,7 +49,7 @@
 #define FAN1_PIN 35
 #define FAN2_PIN 36
 #define FAN_SOFT_PWM
-#define CONTROLLERFAN_PIN 36
+#define CONTROLLERFAN_PIN FAN2_PIN
 #define PS_ON_PIN -1
 #define KILL_PIN -1
 

Marlin/planner.cpp

@@ -93,6 +93,10 @@ unsigned long axis_steps_per_sqr_second[NUM_AXIS];
   bool autotemp_enabled = false;
 #endif
 
+#if ENABLED(FAN_SOFT_PWM)
+  extern unsigned char fanSpeedSoftPwm[FAN_COUNT];
+#endif
+
 //===========================================================================
 //============ semi-private variables, used in inline functions =============
 //===========================================================================
@@ -399,7 +403,12 @@ void plan_init() {
 
 void check_axes_activity() {
   unsigned char axis_active[NUM_AXIS] = { 0 },
-                tail_fan_speed = fanSpeed;
+                tail_fan_speed[FAN_COUNT];
+
+  #if FAN_COUNT > 0
+    for (uint8_t i = 0; i < FAN_COUNT; i++) tail_fan_speed[i] = fanSpeeds[i];
+  #endif
+
   #if ENABLED(BARICUDA)
     unsigned char tail_valve_pressure = ValvePressure,
                   tail_e_to_p_pressure = EtoPPressure;
@@ -408,13 +417,19 @@ void check_axes_activity() {
   block_t* block;
 
   if (blocks_queued()) {
+
     uint8_t block_index = block_buffer_tail;
-    tail_fan_speed = block_buffer[block_index].fan_speed;
+
+    #if FAN_COUNT > 0
+      for (uint8_t i = 0; i < FAN_COUNT; i++) tail_fan_speed[i] = block_buffer[block_index].fan_speed[i];
+    #endif
+
     #if ENABLED(BARICUDA)
       block = &block_buffer[block_index];
       tail_valve_pressure = block->valve_pressure;
       tail_e_to_p_pressure = block->e_to_p_pressure;
     #endif
+
     while (block_index != block_buffer_head) {
       block = &block_buffer[block_index];
       for (int i = 0; i < NUM_AXIS; i++) if (block->steps[i]) axis_active[i]++;
@@ -439,32 +454,65 @@ void check_axes_activity() {
     }
   #endif
 
-  #if HAS_FAN
+  #if FAN_COUNT > 0
-    #ifdef FAN_KICKSTART_TIME
+
-      static millis_t fan_kick_end = 0;
-      if (tail_fan_speed) {
-        millis_t ms = millis();
-        if (fan_kick_end == 0) {
-          fan_kick_end = ms + FAN_KICKSTART_TIME;
-          tail_fan_speed = 255; // Starting up.
-        }
-        else if (ms < fan_kick_end)
-          tail_fan_speed = 255; // Still spinning up.
-        else
-          fan_kick_end = 0;
-      }
-    #endif //FAN_KICKSTART_TIME
     #if defined(FAN_MIN_PWM)
-      #define CALC_FAN_SPEED (tail_fan_speed ? ( FAN_MIN_PWM + (tail_fan_speed * (255 - (FAN_MIN_PWM))) / 255 ) : 0)
+      #define CALC_FAN_SPEED(f) (tail_fan_speed[f] ? ( FAN_MIN_PWM + (tail_fan_speed[f] * (255 - FAN_MIN_PWM)) / 255 ) : 0)
     #else
-      #define CALC_FAN_SPEED tail_fan_speed
+      #define CALC_FAN_SPEED(f) tail_fan_speed[f]
-    #endif // FAN_MIN_PWM
+    #endif
+
+    #ifdef FAN_KICKSTART_TIME
+
+      static millis_t fan_kick_end[FAN_COUNT] = { 0 }, ms = millis();
+
+      #define KICKSTART_FAN(f) \
+        if (tail_fan_speed[f]) { \
+          if (fan_kick_end[f] == 0) { \
+            fan_kick_end[f] = ms + FAN_KICKSTART_TIME; \
+            tail_fan_speed[f] = 255; \
+          } \
+          else if (fan_kick_end[f] > ms) \
+            tail_fan_speed[f] = 255; \
+          else \
+            fan_kick_end[f] = 0; \
+        }
+
+      #if HAS_FAN0
+        KICKSTART_FAN(0);
+      #endif
+      #if HAS_FAN1
+        KICKSTART_FAN(1);
+      #endif
+      #if HAS_FAN2
+        KICKSTART_FAN(2);
+      #endif
+
+    #endif //FAN_KICKSTART_TIME
+
     #if ENABLED(FAN_SOFT_PWM)
-      fanSpeedSoftPwm = CALC_FAN_SPEED;
+      #if HAS_FAN0
+        fanSpeedSoftPwm[0] = CALC_FAN_SPEED(0);
+      #endif
+      #if HAS_FAN1
+        fanSpeedSoftPwm[1] = CALC_FAN_SPEED(1);
+      #endif
+      #if HAS_FAN2
+        fanSpeedSoftPwm[2] = CALC_FAN_SPEED(2);
+      #endif
     #else
-      analogWrite(FAN_PIN, CALC_FAN_SPEED);
+      #if HAS_FAN0
-    #endif // FAN_SOFT_PWM
+        analogWrite(FAN_PIN, CALC_FAN_SPEED(0));
-  #endif // HAS_FAN
+      #endif
+      #if HAS_FAN1
+        analogWrite(FAN1_PIN, CALC_FAN_SPEED(1));
+      #endif
+      #if HAS_FAN2
+        analogWrite(FAN2_PIN, CALC_FAN_SPEED(2));
+      #endif
+    #endif
+
+  #endif // FAN_COUNT > 0
 
   #if ENABLED(AUTOTEMP)
     getHighESpeed();
@@ -576,7 +624,10 @@ float junction_deviation = 0.1;
   // Bail if this is a zero-length block
   if (block->step_event_count <= dropsegments) return;
 
-  block->fan_speed = fanSpeed;
+  #if FAN_COUNT > 0
+    for (uint8_t i = 0; i < FAN_COUNT; i++) block->fan_speed[i] = fanSpeeds[i];
+  #endif
+
   #if ENABLED(BARICUDA)
     block->valve_pressure = ValvePressure;
     block->e_to_p_pressure = EtoPPressure;

Marlin/planner.h

@@ -59,12 +59,18 @@ typedef struct {
   unsigned long initial_rate;                        // The jerk-adjusted step rate at start of block
   unsigned long final_rate;                          // The minimal rate at exit
   unsigned long acceleration_st;                     // acceleration steps/sec^2
-  unsigned long fan_speed;
+
+  #if FAN_COUNT > 0
+    unsigned long fan_speed[FAN_COUNT];
+  #endif
+
   #if ENABLED(BARICUDA)
     unsigned long valve_pressure;
     unsigned long e_to_p_pressure;
   #endif
+
   volatile char busy;
+
 } block_t;
 
 #define BLOCK_MOD(n) ((n)&(BLOCK_BUFFER_SIZE-1))

Marlin/temperature.cpp

@@ -62,7 +62,7 @@ float current_temperature_bed = 0.0;
 #endif //PIDTEMPBED
 
 #if ENABLED(FAN_SOFT_PWM)
-  unsigned char fanSpeedSoftPwm;
+  unsigned char fanSpeedSoftPwm[FAN_COUNT];
 #endif
 
 unsigned char soft_pwm_bed;
@@ -130,7 +130,7 @@ static volatile bool temp_meas_ready = false;
 static unsigned char soft_pwm[EXTRUDERS];
 
 #if ENABLED(FAN_SOFT_PWM)
-  static unsigned char soft_pwm_fan;
+  static unsigned char soft_pwm_fan[FAN_COUNT];
 #endif
 #if HAS_AUTO_FAN
   static millis_t next_auto_fan_check_ms;
@@ -886,17 +886,40 @@ void tp_init() {
   #if HAS_HEATER_BED
     SET_OUTPUT(HEATER_BED_PIN);
   #endif
-  #if HAS_FAN
+
   #if ENABLED(FAST_PWM_FAN) || ENABLED(FAN_SOFT_PWM)
+
+    #if HAS_FAN0
       SET_OUTPUT(FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
         setPwmFrequency(FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
       #endif
       #if ENABLED(FAN_SOFT_PWM)
-        soft_pwm_fan = fanSpeedSoftPwm / 2;
+        soft_pwm_fan[0] = fanSpeedSoftPwm[0] / 2;
       #endif
     #endif
+
+    #if HAS_FAN1
+      SET_OUTPUT(FAN1_PIN);
+      #if ENABLED(FAST_PWM_FAN)
+        setPwmFrequency(FAN1_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
       #endif
+      #if ENABLED(FAN_SOFT_PWM)
+        soft_pwm_fan[1] = fanSpeedSoftPwm[1] / 2;
+      #endif
+    #endif
+
+    #if HAS_FAN2
+      SET_OUTPUT(FAN2_PIN);
+      #if ENABLED(FAST_PWM_FAN)
+        setPwmFrequency(FAN2_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      #endif
+      #if ENABLED(FAN_SOFT_PWM)
+        soft_pwm_fan[2] = fanSpeedSoftPwm[2] / 2;
+      #endif
+    #endif
+
+  #endif // FAST_PWM_FAN || FAN_SOFT_PWM
 
   #if ENABLED(HEATER_0_USES_MAX6675)
 
@@ -1320,9 +1343,20 @@ ISR(TIMER0_COMPB_vect) {
         soft_pwm_BED = soft_pwm_bed;
         WRITE_HEATER_BED(soft_pwm_BED > 0 ? 1 : 0);
       #endif
+
       #if ENABLED(FAN_SOFT_PWM)
-        soft_pwm_fan = fanSpeedSoftPwm / 2;
+        #if HAS_FAN0
-        WRITE_FAN(soft_pwm_fan > 0 ? 1 : 0);
+          soft_pwm_fan[0] = fanSpeedSoftPwm[0] / 2;
+          WRITE_FAN(soft_pwm_fan[0] > 0 ? 1 : 0);
+        #endif
+        #if HAS_FAN1
+          soft_pwm_fan[1] = fanSpeedSoftPwm[1] / 2;
+          WRITE_FAN1(soft_pwm_fan[1] > 0 ? 1 : 0);
+        #endif
+        #if HAS_FAN2
+          soft_pwm_fan[2] = fanSpeedSoftPwm[2] / 2;
+          WRITE_FAN2(soft_pwm_fan[2] > 0 ? 1 : 0);
+        #endif
       #endif
     }
 
@@ -1342,7 +1376,15 @@ ISR(TIMER0_COMPB_vect) {
     #endif
 
     #if ENABLED(FAN_SOFT_PWM)
-      if (soft_pwm_fan < pwm_count) WRITE_FAN(0);
+      #if HAS_FAN0
+        if (soft_pwm_fan[0] < pwm_count) WRITE_FAN(0);
+      #endif
+      #if HAS_FAN1
+        if (soft_pwm_fan[1] < pwm_count) WRITE_FAN1(0);
+      #endif
+      #if HAS_FAN2
+        if (soft_pwm_fan[2] < pwm_count) WRITE_FAN2(0);
+      #endif
     #endif
 
     pwm_count += _BV(SOFT_PWM_SCALE);
@@ -1421,10 +1463,28 @@ ISR(TIMER0_COMPB_vect) {
 
     #if ENABLED(FAN_SOFT_PWM)
       if (pwm_count == 0) {
-        soft_pwm_fan = fanSpeedSoftPwm / 2;
+        #if HAS_FAN0
-        WRITE_FAN(soft_pwm_fan > 0 ? 1 : 0);
+          soft_pwm_fan[0] = fanSpeedSoftPwm[0] / 2;
+          WRITE_FAN(soft_pwm_fan[0] > 0 ? 1 : 0);
+        #endif
+        #if HAS_FAN1
+          soft_pwm_fan[1] = fanSpeedSoftPwm[1] / 2;
+          WRITE_FAN1(soft_pwm_fan[1] > 0 ? 1 : 0);
+        #endif
+        #if HAS_FAN2
+          soft_pwm_fan[2] = fanSpeedSoftPwm[2] / 2;
+          WRITE_FAN2(soft_pwm_fan[2] > 0 ? 1 : 0);
+        #endif
       }
-      if (soft_pwm_fan < pwm_count) WRITE_FAN(0);
+      #if HAS_FAN0
+        if (soft_pwm_fan[0] < pwm_count) WRITE_FAN(0);
+      #endif
+      #if HAS_FAN1
+        if (soft_pwm_fan[1] < pwm_count) WRITE_FAN1(0);
+      #endif
+      #if HAS_FAN2
+        if (soft_pwm_fan[2] < pwm_count) WRITE_FAN2(0);
+      #endif
     #endif //FAN_SOFT_PWM
 
     pwm_count += _BV(SOFT_PWM_SCALE);

Marlin/ultralcd.cpp

@@ -614,7 +614,22 @@ static void lcd_tune_menu() {
   //
   // Fan Speed:
   //
-  MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED, &fanSpeed, 0, 255);
+  #if FAN_COUNT > 0
+    #if HAS_FAN0
+      #if FAN_COUNT > 1
+        #define MSG_1ST_FAN_SPEED MSG_FAN_SPEED " 1"
+      #else
+        #define MSG_1ST_FAN_SPEED MSG_FAN_SPEED
+      #endif
+      MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_1ST_FAN_SPEED, &fanSpeeds[0], 0, 255);
+    #endif
+    #if HAS_FAN1
+      MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED " 2", &fanSpeeds[1], 0, 255);
+    #endif
+    #if HAS_FAN2
+      MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED " 3", &fanSpeeds[2], 0, 255);
+    #endif
+  #endif // FAN_COUNT > 0
 
   //
   // Flow:
@@ -665,7 +680,13 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
   #if TEMP_SENSOR_BED != 0
     setTargetBed(tempb);
   #endif
-  fanSpeed = fan;
+  #if FAN_COUNT > 0
+    #if FAN_COUNT > 1
+      fanSpeeds[active_extruder < FAN_COUNT ? active_extruder : 0] = fan;
+    #else
+      fanSpeeds[0] = fan;
+    #endif
+  #endif
   lcd_return_to_status();
 }
 
@@ -755,8 +776,10 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
 #endif // TEMP_SENSOR_0 && (TEMP_SENSOR_1 || TEMP_SENSOR_2 || TEMP_SENSOR_3 || TEMP_SENSOR_BED)
 
 void lcd_cooldown() {
+  #if FAN_COUNT > 0
+    for (uint8_t i = 0; i < FAN_COUNT; i++) fanSpeeds[i] = 0;
+  #endif
   disable_all_heaters();
-  fanSpeed = 0;
   lcd_return_to_status();
 }
 
@@ -1125,7 +1148,22 @@ static void lcd_control_temperature_menu() {
   //
   // Fan Speed:
   //
-  MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED, &fanSpeed, 0, 255);
+  #if FAN_COUNT > 0
+    #if HAS_FAN0
+      #if FAN_COUNT > 1
+        #define MSG_1ST_FAN_SPEED MSG_FAN_SPEED " 1"
+      #else
+        #define MSG_1ST_FAN_SPEED MSG_FAN_SPEED
+      #endif
+      MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_1ST_FAN_SPEED, &fanSpeeds[0], 0, 255);
+    #endif
+    #if HAS_FAN1
+      MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED " 2", &fanSpeeds[1], 0, 255);
+    #endif
+    #if HAS_FAN2
+      MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED " 3", &fanSpeeds[2], 0, 255);
+    #endif
+  #endif // FAN_COUNT > 0
 
   //
   // Autotemp, Min, Max, Fact

Marlin/ultralcd_implementation_hitachi_HD44780.h

@@ -873,16 +873,34 @@ void lcd_implementation_drawedit(const char* pstr, char* value) {
     // Set the LEDS - referred to as backlights by the LiquidTWI2 library
     static uint8_t ledsprev = 0;
     uint8_t leds = 0;
+
     if (target_temperature_bed > 0) leds |= LED_A;
+
     if (target_temperature[0] > 0) leds |= LED_B;
-    if (fanSpeed) leds |= LED_C;
+
+    #if FAN_COUNT > 0
+      if (0
+        #if HAS_FAN0
+          || fanSpeeds[0]
+        #endif
+        #if HAS_FAN1
+          || fanSpeeds[1]
+        #endif
+        #if HAS_FAN2
+          || fanSpeeds[2]
+        #endif
+      ) leds |= LED_C;
+    #endif // FAN_COUNT > 0
+
     #if EXTRUDERS > 1
       if (target_temperature[1] > 0) leds |= LED_C;
     #endif
+
     if (leds != ledsprev) {
       lcd.setBacklight(leds);
       ledsprev = leds;
     }
+
   }
 
 #endif // LCD_HAS_STATUS_INDICATORS