Add POWER_LOSS_PIN support

Marlin/Configuration_adv.h

@@ -589,6 +589,10 @@
    * point in the file.
    */
   //#define POWER_LOSS_RECOVERY
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    //#define POWER_LOSS_PIN   44     // Pin to detect power loss
+    //#define POWER_LOSS_STATE HIGH   // State of pin indicating power loss
+  #endif
 
   /**
    * Sort SD file listings in alphabetical order.

Marlin/src/config/default/Configuration_adv.h

@@ -589,6 +589,10 @@
    * point in the file.
    */
   //#define POWER_LOSS_RECOVERY
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    //#define POWER_LOSS_PIN   44     // Pin to detect power loss
+    //#define POWER_LOSS_STATE HIGH   // State of pin indicating power loss
+  #endif
 
   /**
    * Sort SD file listings in alphabetical order.

Marlin/src/feature/power_loss_recovery.cpp

@@ -202,12 +202,19 @@ void save_job_recovery_info() {
     millis_t ms = millis();
   #endif
   if (
-    #if SAVE_INFO_INTERVAL_MS > 0
-      ELAPSED(ms, next_save_ms) ||
-    #endif
+    // Save on every command
     #if ENABLED(SAVE_EACH_CMD_MODE)
       true
     #else
+      // Save if power loss pin is triggered
+      #if PIN_EXISTS(POWER_LOSS)
+        READ(POWER_LOSS_PIN) == POWER_LOSS_STATE ||
+      #endif
+      // Save if interval is elapsed
+      #if SAVE_INFO_INTERVAL_MS > 0
+        ELAPSED(ms, next_save_ms) ||
+      #endif
+      // Save on every new Z height
       (current_position[Z_AXIS] > 0 && current_position[Z_AXIS] > job_recovery_info.current_position[Z_AXIS])
     #endif
   ) {
@@ -267,6 +274,11 @@ void save_job_recovery_info() {
 
     card.openJobRecoveryFile(false);
     (void)card.saveJobRecoveryInfo();
+
+    // If power-loss pin was triggered, write just once then kill
+    #if PIN_EXISTS(POWER_LOSS)
+      if (READ(POWER_LOSS_PIN) == POWER_LOSS_STATE) kill(MSG_POWER_LOSS_RECOVERY);
+    #endif
   }
 }
 

buildroot/share/tests/megaatmega2560_tests

@@ -27,7 +27,7 @@ opt_enable PIDTEMPBED FIX_MOUNTED_PROBE Z_SAFE_HOMING
 opt_enable REPRAP_DISCOUNT_SMART_CONTROLLER SDSUPPORT EEPROM_SETTINGS PINS_DEBUGGING
 opt_enable BLINKM PCA9632 RGB_LED NEOPIXEL_LED AUTO_POWER_CONTROL NOZZLE_PARK_FEATURE FILAMENT_RUNOUT_SENSOR
 opt_enable AUTO_BED_LEVELING_LINEAR Z_MIN_PROBE_REPEATABILITY_TEST DEBUG_LEVELING_FEATURE SKEW_CORRECTION SKEW_CORRECTION_FOR_Z SKEW_CORRECTION_GCODE
-opt_enable_adv ARC_P_CIRCLES ADVANCED_PAUSE_FEATURE CNC_WORKSPACE_PLANES CNC_COORDINATE_SYSTEMS POWER_LOSS_RECOVERY
+opt_enable_adv ARC_P_CIRCLES ADVANCED_PAUSE_FEATURE CNC_WORKSPACE_PLANES CNC_COORDINATE_SYSTEMS POWER_LOSS_RECOVERY POWER_LOSS_PIN POWER_LOSS_STATE
 opt_enable_adv FWRETRACT MAX7219_DEBUG LED_CONTROL_MENU CASE_LIGHT_ENABLE CASE_LIGHT_USE_NEOPIXEL CODEPENDENT_XY_HOMING
 opt_set GRID_MAX_POINTS_X 16
 opt_set_adv FANMUX0_PIN 53