New feature: Part-Cooling Fan Multiplexer

.travis.yml

   - opt_enable_adv FWRETRACT
   - opt_set ABL_GRID_POINTS_X 16
   - opt_set ABL_GRID_POINTS_Y 16
+  - opt_set_adv FANMUX0_PIN 53
   - build_marlin
   #
   # Test a simple build of AUTO_BED_LEVELING_UBL

Marlin/Conditionals_post.h

   #define WRITE_FAN_N(n, v) WRITE_FAN##n(v)
 
   /**
+   * Part Cooling fan multipliexer
+   */
+  #define HAS_FANMUX PIN_EXISTS(FANMUX0)
+
+  /**
    * Servos and probes
    */
 

Marlin/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/Marlin_main.cpp

 
 #endif // PARKING_EXTRUDER
 
+#if HAS_FANMUX
+
+  void fanmux_switch(const uint8_t e) {
+    WRITE(FANMUX0_PIN, TEST(e, 0) ? HIGH : LOW);
+    #if PIN_EXISTS(FANMUX1)
+      WRITE(FANMUX1_PIN, TEST(e, 1) ? HIGH : LOW);
+      #if PIN_EXISTS(FANMUX2)
+        WRITE(FANMUX2, TEST(e, 2) ? HIGH : LOW);
+      #endif
+    #endif
+  }
+
+  FORCE_INLINE void fanmux_init(void){
+    SET_OUTPUT(FANMUX0_PIN);
+    #if PIN_EXISTS(FANMUX1)
+      SET_OUTPUT(FANMUX1_PIN);
+      #if PIN_EXISTS(FANMUX2)
+        SET_OUTPUT(FANMUX2_PIN);
+      #endif 
+    #endif
+    fanmux_switch(0);
+  }
+
+#endif // HAS_FANMUX
+
 /**
  * Perform a tool-change, which may result in moving the
  * previous tool out of the way and the new tool into place.
           current_position[Y_AXIS] -= hotend_offset[Y_AXIS][active_extruder] - hotend_offset[Y_AXIS][tmp_extruder];
           current_position[Z_AXIS] -= hotend_offset[Z_AXIS][active_extruder] - hotend_offset[Z_AXIS][tmp_extruder];
 
-          // Activate the new extruder
+          // Activate the new extruder ahead of calling set_axis_is_at_home!
           active_extruder = tmp_extruder;
 
           // This function resets the max/min values - the current position may be overwritten below.
         select_multiplexed_stepper(tmp_extruder);
       #endif
 
+      // Set the new active extruder
+      active_extruder = tmp_extruder;
+
     #endif // HOTENDS <= 1
 
     #if ENABLED(SWITCHING_EXTRUDER) && !DONT_SWITCH
       stepper.synchronize();
-      move_extruder_servo(tmp_extruder);
+      move_extruder_servo(active_extruder);
     #endif
 
-    active_extruder = tmp_extruder;
+    #if HAS_FANMUX
+      fanmux_switch(active_extruder);
+    #endif
 
     SERIAL_ECHO_START();
     SERIAL_ECHOLNPAIR(MSG_ACTIVE_EXTRUDER, (int)active_extruder);
     SET_OUTPUT(E_MUX1_PIN);
     SET_OUTPUT(E_MUX2_PIN);
   #endif
-
+  
+  #if HAS_FANMUX
+    fanmux_init();
+  #endif
+  
   lcd_init();
 
   #ifndef CUSTOM_BOOTSCREEN_TIMEOUT

Marlin/SanityCheck.h

   #endif
 #endif
 
+/**
+ * Part-Cooling Fan Multiplexer requirements
+ */
+#if PIN_EXISTS(FANMUX1)
+  #if !HAS_FANMUX
+    #error "FANMUX0_PIN must be set before FANMUX1_PIN can be set."
+  #endif
+#elif PIN_EXISTS(FANMUX2)
+  #error "FANMUX0_PIN and FANMUX1_PIN must be set before FANMUX2_PIN can be set."
+#endif
 
 /**
  * Limited number of servos

Marlin/example_configurations/AlephObjects/TAZ4/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Anet/A6/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Anet/A8/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/BQ/Hephestos/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/BQ/Hephestos_2/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/BQ/WITBOX/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Cartesio/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Felix/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Folger Tech/i3-2020/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Infitary/i3-M508/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Malyan/M150/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/RigidBot/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/SCARA/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/TinyBoy2/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Velleman/K8200/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/Velleman/K8400/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/delta/FLSUN/auto_calibrate/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/delta/FLSUN/kossel_mini/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/delta/generic/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/gCreate/gMax1.5+/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/makibox/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/example_configurations/wt150/Configuration_adv.h

 #define EXTRUDER_AUTO_FAN_SPEED   255  // == full speed
 
 /**
+ * Part-Cooling Fan Multiplexer
+ * 
+ * This feature allows you to digitally multiplex the fan output.
+ * The multiplexer is automatically switched at tool-change.
+ * Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans.
+ */
+#define FANMUX0_PIN -1
+#define FANMUX1_PIN -1
+#define FANMUX2_PIN -1
+
+/**
  * M355 Case Light on-off / brightness
  */
 //#define CASE_LIGHT_ENABLE

Marlin/pins.h

   #define CONTROLLER_FAN_PIN  -1
 #endif
 
+#ifndef FANMUX0_PIN
+  #define FANMUX0_PIN -1
+#endif
+#ifndef FANMUX1_PIN
+  #define FANMUX1_PIN -1
+#endif
+#ifndef FANMUX2_PIN
+  #define FANMUX2_PIN -1
+#endif
+
 #ifndef HEATER_0_PIN
   #define HEATER_0_PIN -1
 #endif