Update SKR mini configs

config/examples/BigTreeTech/SKR Mini E3 1.0/Configuration_adv.h

@@ -197,6 +197,56 @@
     #define DEFAULT_Kc (100) //heating power=Kc*(e_speed)
     #define LPQ_MAX_LEN 50
   #endif
+
+  /**
+   * Add an experimental additional term to the heater power, proportional to the fan speed.
+   * A well-chosen Kf value should add just enough power to compensate for power-loss from the cooling fan.
+   * You can either just add a constant compensation with the DEFAULT_Kf value
+   * or follow the instruction below to get speed-dependent compensation.
+   *
+   * Constant compensation (use only with fanspeeds of 0% and 100%)
+   * ---------------------------------------------------------------------
+   * A good starting point for the Kf-value comes from the calculation:
+   *   kf = (power_fan * eff_fan) / power_heater * 255
+   * where eff_fan is between 0.0 and 1.0, based on fan-efficiency and airflow to the nozzle / heater.
+   *
+   * Example:
+   *   Heater: 40W, Fan: 0.1A * 24V = 2.4W, eff_fan = 0.8
+   *   Kf = (2.4W * 0.8) / 40W * 255 = 12.24
+   *
+   * Fan-speed dependent compensation
+   * --------------------------------
+   * 1. To find a good Kf value, set the hotend temperature, wait for it to settle, and enable the fan (100%).
+   *    Make sure PID_FAN_SCALING_LIN_FACTOR is 0 and PID_FAN_SCALING_ALTERNATIVE_DEFINITION is not enabled.
+   *    If you see the temperature drop repeat the test, increasing the Kf value slowly, until the temperature
+   *    drop goes away. If the temperature overshoots after enabling the fan, the Kf value is too big.
+   * 2. Note the Kf-value for fan-speed at 100%
+   * 3. Determine a good value for PID_FAN_SCALING_MIN_SPEED, which is around the speed, where the fan starts moving.
+   * 4. Repeat step 1. and 2. for this fan speed.
+   * 5. Enable PID_FAN_SCALING_ALTERNATIVE_DEFINITION and enter the two identified Kf-values in
+   *    PID_FAN_SCALING_AT_FULL_SPEED and PID_FAN_SCALING_AT_MIN_SPEED. Enter the minimum speed in PID_FAN_SCALING_MIN_SPEED
+   */
+  //#define PID_FAN_SCALING
+  #if ENABLED(PID_FAN_SCALING)
+    //#define PID_FAN_SCALING_ALTERNATIVE_DEFINITION
+    #if ENABLED(PID_FAN_SCALING_ALTERNATIVE_DEFINITION)
+      // The alternative definition is used for an easier configuration.
+      // Just figure out Kf at fullspeed (255) and PID_FAN_SCALING_MIN_SPEED.
+      // DEFAULT_Kf and PID_FAN_SCALING_LIN_FACTOR are calculated accordingly.
+
+      #define PID_FAN_SCALING_AT_FULL_SPEED 13.0        //=PID_FAN_SCALING_LIN_FACTOR*255+DEFAULT_Kf
+      #define PID_FAN_SCALING_AT_MIN_SPEED 6.0          //=PID_FAN_SCALING_LIN_FACTOR*PID_FAN_SCALING_MIN_SPEED+DEFAULT_Kf
+      #define PID_FAN_SCALING_MIN_SPEED 10.0            // Minimum fan speed at which to enable PID_FAN_SCALING
+
+      #define DEFAULT_Kf (255.0*PID_FAN_SCALING_AT_MIN_SPEED-PID_FAN_SCALING_AT_FULL_SPEED*PID_FAN_SCALING_MIN_SPEED)/(255.0-PID_FAN_SCALING_MIN_SPEED)
+      #define PID_FAN_SCALING_LIN_FACTOR (PID_FAN_SCALING_AT_FULL_SPEED-DEFAULT_Kf)/255.0
+
+    #else
+      #define PID_FAN_SCALING_LIN_FACTOR (0)             // Power loss due to cooling = Kf * (fan_speed)
+      #define DEFAULT_Kf 10                              // A constant value added to the PID-tuner
+      #define PID_FAN_SCALING_MIN_SPEED 10               // Minimum fan speed at which to enable PID_FAN_SCALING
+    #endif
+  #endif
 #endif
 
 /**
@@ -960,6 +1010,8 @@
    */
   //#define POWER_LOSS_RECOVERY
   #if ENABLED(POWER_LOSS_RECOVERY)
+    //#define BACKUP_POWER_SUPPLY       // Backup power / UPS to move the steppers on power loss
+    //#define POWER_LOSS_ZRAISE       2 // (mm) Z axis raise on resume (on power loss with UPS)
     //#define POWER_LOSS_PIN         44 // Pin to detect power loss
     //#define POWER_LOSS_STATE     HIGH // State of pin indicating power loss
     //#define POWER_LOSS_PULL           // Set pullup / pulldown as appropriate

config/examples/BigTreeTech/SKR Mini E3 1.2/Configuration_adv.h

@@ -197,6 +197,56 @@
     #define DEFAULT_Kc (100) //heating power=Kc*(e_speed)
     #define LPQ_MAX_LEN 50
   #endif
+
+  /**
+   * Add an experimental additional term to the heater power, proportional to the fan speed.
+   * A well-chosen Kf value should add just enough power to compensate for power-loss from the cooling fan.
+   * You can either just add a constant compensation with the DEFAULT_Kf value
+   * or follow the instruction below to get speed-dependent compensation.
+   *
+   * Constant compensation (use only with fanspeeds of 0% and 100%)
+   * ---------------------------------------------------------------------
+   * A good starting point for the Kf-value comes from the calculation:
+   *   kf = (power_fan * eff_fan) / power_heater * 255
+   * where eff_fan is between 0.0 and 1.0, based on fan-efficiency and airflow to the nozzle / heater.
+   *
+   * Example:
+   *   Heater: 40W, Fan: 0.1A * 24V = 2.4W, eff_fan = 0.8
+   *   Kf = (2.4W * 0.8) / 40W * 255 = 12.24
+   *
+   * Fan-speed dependent compensation
+   * --------------------------------
+   * 1. To find a good Kf value, set the hotend temperature, wait for it to settle, and enable the fan (100%).
+   *    Make sure PID_FAN_SCALING_LIN_FACTOR is 0 and PID_FAN_SCALING_ALTERNATIVE_DEFINITION is not enabled.
+   *    If you see the temperature drop repeat the test, increasing the Kf value slowly, until the temperature
+   *    drop goes away. If the temperature overshoots after enabling the fan, the Kf value is too big.
+   * 2. Note the Kf-value for fan-speed at 100%
+   * 3. Determine a good value for PID_FAN_SCALING_MIN_SPEED, which is around the speed, where the fan starts moving.
+   * 4. Repeat step 1. and 2. for this fan speed.
+   * 5. Enable PID_FAN_SCALING_ALTERNATIVE_DEFINITION and enter the two identified Kf-values in
+   *    PID_FAN_SCALING_AT_FULL_SPEED and PID_FAN_SCALING_AT_MIN_SPEED. Enter the minimum speed in PID_FAN_SCALING_MIN_SPEED
+   */
+  //#define PID_FAN_SCALING
+  #if ENABLED(PID_FAN_SCALING)
+    //#define PID_FAN_SCALING_ALTERNATIVE_DEFINITION
+    #if ENABLED(PID_FAN_SCALING_ALTERNATIVE_DEFINITION)
+      // The alternative definition is used for an easier configuration.
+      // Just figure out Kf at fullspeed (255) and PID_FAN_SCALING_MIN_SPEED.
+      // DEFAULT_Kf and PID_FAN_SCALING_LIN_FACTOR are calculated accordingly.
+
+      #define PID_FAN_SCALING_AT_FULL_SPEED 13.0        //=PID_FAN_SCALING_LIN_FACTOR*255+DEFAULT_Kf
+      #define PID_FAN_SCALING_AT_MIN_SPEED 6.0          //=PID_FAN_SCALING_LIN_FACTOR*PID_FAN_SCALING_MIN_SPEED+DEFAULT_Kf
+      #define PID_FAN_SCALING_MIN_SPEED 10.0            // Minimum fan speed at which to enable PID_FAN_SCALING
+
+      #define DEFAULT_Kf (255.0*PID_FAN_SCALING_AT_MIN_SPEED-PID_FAN_SCALING_AT_FULL_SPEED*PID_FAN_SCALING_MIN_SPEED)/(255.0-PID_FAN_SCALING_MIN_SPEED)
+      #define PID_FAN_SCALING_LIN_FACTOR (PID_FAN_SCALING_AT_FULL_SPEED-DEFAULT_Kf)/255.0
+
+    #else
+      #define PID_FAN_SCALING_LIN_FACTOR (0)             // Power loss due to cooling = Kf * (fan_speed)
+      #define DEFAULT_Kf 10                              // A constant value added to the PID-tuner
+      #define PID_FAN_SCALING_MIN_SPEED 10               // Minimum fan speed at which to enable PID_FAN_SCALING
+    #endif
+  #endif
 #endif
 
 /**