Power Loss Recovery with a UPS (#15943)

Marlin/src/feature/power_loss_recovery.cpp

@@ -65,6 +65,9 @@ PrintJobRecovery recovery;
 #ifndef POWER_LOSS_RETRACT_LEN
   #define POWER_LOSS_RETRACT_LEN 0
 #endif
+#ifndef POWER_LOSS_ZRAISE
+  #define POWER_LOSS_ZRAISE 2
+#endif
 
 /**
  * Clear the recovery info
@@ -235,10 +238,34 @@ void PrintJobRecovery::save(const bool force/*=false*/, const bool save_queue/*=
 }
 
 #if PIN_EXISTS(POWER_LOSS)
+
   void PrintJobRecovery::_outage() {
-    save(true);
+    #if ENABLED(BACKUP_POWER_SUPPLY)
+      static bool lock = false;
+      if (lock) return; // No re-entrance from idle() during raise_z()
+      lock = true;
+    #endif
+    if (IS_SD_PRINTING()) save(true);
+    #if ENABLED(BACKUP_POWER_SUPPLY)
+      raise_z();
+    #endif
+
     kill(GET_TEXT(MSG_OUTAGE_RECOVERY));
   }
+
+  #if ENABLED(BACKUP_POWER_SUPPLY)
+
+    void PrintJobRecovery::raise_z() {
+      // Disable all heaters to reduce power loss
+      thermalManager.disable_all_heaters();
+      quickstop_stepper();
+      // Raise Z axis
+      gcode.process_subcommands_now_P(PSTR("G91\nG0 Z" STRINGIFY(POWER_LOSS_ZRAISE)));
+      planner.synchronize();
+    }
+
+  #endif
+
 #endif
 
 /**
@@ -260,8 +287,6 @@ void PrintJobRecovery::write() {
  */
 void PrintJobRecovery::resume() {
 
-  #define RECOVERY_ZRAISE 2
-
   const uint32_t resume_sdpos = info.sdpos; // Get here before the stepper ISR overwrites it
 
   #if HAS_LEVELING
@@ -272,15 +297,27 @@ void PrintJobRecovery::resume() {
   // Reset E, raise Z, home XY...
   gcode.process_subcommands_now_P(PSTR("G92.9 E0"
     #if Z_HOME_DIR > 0
-      // If Z homing goes to max, reset E and home all
-      "\nG28R0"
+
+      // If Z homing goes to max, just reset E and home all
+      "\n"
+      "G28R0"
       #if ENABLED(MARLIN_DEV_MODE)
         "S"
       #endif
-    #else
+
+    #else // "G92.9 E0 ..."
+
       // Set Z to 0, raise Z by RECOVERY_ZRAISE, and Home (XY only for Cartesian)
       // with no raise. (Only do simulated homing in Marlin Dev Mode.)
-      "Z0\nG1Z" STRINGIFY(RECOVERY_ZRAISE) "\nG28R0"
+      #if ENABLED(BACKUP_POWER_SUPPLY)
+        "Z" STRINGIFY(POWER_LOSS_ZRAISE)    // Z-axis was already raised at outage
+      #else
+        "Z0\n"                              // Set Z=0
+        "G1Z" STRINGIFY(POWER_LOSS_ZRAISE)  // Raise Z
+      #endif
+      "\n"
+
+      "G28R0"
       #if ENABLED(MARLIN_DEV_MODE)
         "S"
       #elif !IS_KINEMATIC

Marlin/src/feature/power_loss_recovery.h

@@ -168,7 +168,7 @@ class PrintJobRecovery {
 
   #if PIN_EXISTS(POWER_LOSS)
     static inline void outage() {
-      if (enabled && IS_SD_PRINTING() && READ(POWER_LOSS_PIN) == POWER_LOSS_STATE)
+      if (enabled && READ(POWER_LOSS_PIN) == POWER_LOSS_STATE)
         _outage();
     }
   #endif
@@ -184,6 +184,10 @@ class PrintJobRecovery {
   private:
     static void write();
 
+  #if ENABLED(BACKUP_POWER_SUPPLY)
+    static void raise_z();
+  #endif
+
   #if PIN_EXISTS(POWER_LOSS)
     static void _outage();
   #endif