First draft: configure extruder fan speed

Author: vovodroid

Marlin/src/lcd/menu/menu_configuration.cpp

@@ -354,6 +354,9 @@ void menu_advanced_settings();
 
   #include "../../feature/controllerfan.h"
 
+namespace LanguageNarrow_en {
+  static LSTR MSG_E_FAN = _UxGT("Extruder fan speed");
+}
   void menu_controller_fan() {
     START_MENU();
     BACK_ITEM(MSG_CONFIGURATION);
@@ -363,6 +366,7 @@ void menu_advanced_settings();
       EDIT_ITEM_FAST(percent, MSG_CONTROLLER_FAN_SPEED, &controllerFan.settings.active_speed, CONTROLLERFAN_SPEED_MIN, 255);
       EDIT_ITEM(uint16_4, MSG_CONTROLLER_FAN_DURATION, &controllerFan.settings.duration, 0, 4800);
     }
+    EDIT_ITEM_FAST(percent, MSG_E_FAN, &Temperature::extruder_fan_speed, 0, 255);
     END_MENU();
   }
 

Marlin/src/module/temperature.cpp

@@ -364,6 +364,8 @@ PGMSTR(str_t_heating_failed, STR_T_HEATING_FAILED);
   uint8_t Temperature::soft_pwm_controller_speed = FAN_OFF_PWM;
 #endif
 
+uint8_t Temperature::extruder_fan_speed = EXTRUDER_AUTO_FAN_SPEED;
+
 // Init fans according to whether they're native PWM or Software PWM
 #ifdef BOARD_OPENDRAIN_MOSFETS
   #define _INIT_SOFT_FAN(P) OUT_WRITE_OD(P, ENABLED(FAN_INVERTING) ? LOW : HIGH)
@@ -1413,7 +1415,7 @@ int16_t Temperature::getHeaterPower(const heater_id_t heater_id) {
       #if ALL(HAS_FANCHECK, HAS_PWMFANCHECK)
         #define _AUTOFAN_SPEED() fan_check.is_measuring() ? 255 : EXTRUDER_AUTO_FAN_SPEED
       #else
-        #define _AUTOFAN_SPEED() EXTRUDER_AUTO_FAN_SPEED
+        #define _AUTOFAN_SPEED() extruder_fan_speed
       #endif
       #define _AUTOFAN_CASE(N) case N: _UPDATE_AUTO_FAN(E##N, fan_on, _AUTOFAN_SPEED()); break;
       #define _AUTOFAN_NOT(N)

Marlin/src/module/temperature.h

@@ -641,6 +641,8 @@ class Temperature {
       static uint8_t soft_pwm_controller_speed;
     #endif
 
+      static uint8_t   extruder_fan_speed;
+
     #if ALL(HAS_MARLINUI_MENU, PREVENT_COLD_EXTRUSION) && E_MANUAL > 0
       static bool allow_cold_extrude_override;
       static void set_menu_cold_override(const bool allow) { allow_cold_extrude_override = allow; }