Fix and improve PowerPanic

- No wait for heatup during host print recovery
- No extra Z lift when power panic happens during paused print
  - added an extra EEPROM value
  - fixed `EEPROM_LAST_ITEM`
  - changed EEPROM version to 3.14.0
- Added `reset_uvlo` function

Firmware/Marlin_main.cpp

@@ -1516,6 +1516,7 @@ void setup()
 		eeprom_update_byte_notify((uint8_t*)EEPROM_TEMP_CAL_ACTIVE, 0);
 	}
 	eeprom_init_default_byte((uint8_t*)EEPROM_UVLO, PowerPanic::NO_PENDING_RECOVERY);
+	eeprom_init_default_byte((uint8_t*)EEPROM_UVLO_Z_LIFTED, 0);
 	eeprom_init_default_byte((uint8_t*)EEPROM_SD_SORT, 0);
 
 	//mbl_mode_init();
@@ -4181,7 +4182,7 @@ void process_commands()
                 enquecommand_P(MSG_M24);
 
                 // Print is recovered, clear the recovery flag
-                eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO, PowerPanic::NO_PENDING_RECOVERY);
+                reset_uvlo();
             } else if (eeprom_read_byte((uint8_t*)EEPROM_UVLO_PRINT_TYPE) == PowerPanic::PRINT_TYPE_HOST) {
                 // For Host prints we need to start the timer so that the pause has any effect
                 // this will allow g-codes to be processed while in the paused state
@@ -11069,7 +11070,7 @@ void restore_print_from_ram_and_continue(float e_move)
 	set_destination_to_current();
 
     restore_print_file_state();
-    eeprom_update_byte((uint8_t*)EEPROM_UVLO, PowerPanic::NO_PENDING_RECOVERY);
+    reset_uvlo();
 	lcd_setstatuspgm(MSG_WELCOME);
     saved_printing_type = PowerPanic::PRINT_TYPE_NONE;
 	saved_printing = false;
@@ -11079,7 +11080,7 @@ void restore_print_from_ram_and_continue(float e_move)
 // Cancel the state related to a currently saved print
 void cancel_saved_printing()
 {
-    eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO, PowerPanic::NO_PENDING_RECOVERY);
+    reset_uvlo();
     saved_start_position[0] = SAVED_START_POSITION_UNSET;
     saved_printing_type = PowerPanic::PRINT_TYPE_NONE;
     saved_printing = false;

Firmware/eeprom.h

@@ -83,7 +83,7 @@ static_assert(sizeof(Sheets) == EEPROM_SHEETS_SIZEOF, "Sizeof(Sheets) is not EEP
 
   To convert hex to dec         https://www.rapidtables.com/convert/number/hex-to-decimal.html
 
-  Version: 1.0.2
+  Version: 3.14.0
 
   ---------------------------------------------------------------------------------
 
@@ -382,6 +382,8 @@ static_assert(sizeof(Sheets) == EEPROM_SHEETS_SIZEOF, "Sizeof(Sheets) is not EEP
 | 0x0C94 3220 | uint8   | EEPROM_KILL_PENDING_FLAG              | 42h, ffh     | ffh                   | Kill pending flag (0x42 magic value)              | kill()       | D3 Ax0c94 C1
 | 0x0C91 3217 | char[3] | EEPROM_FILENAME_EXTENSION             | ???          | ffffffffh             | DOS 8.3 filename extension                        | Power Panic  | D3 Ax0c91 C1
 | 0x0C80 3200 | char[17]| EEPROM_CUSTOM_MENDEL_NAME             | Prusa i3 MK3S| ffffffffffffffffff... | Custom Printer Name                               |              | D3 Ax0c80 C17
+| 0x0C7F 3199 | bool    | EEPROM_UVLO_Z_LIFTED                  | 00h 0        | 00h                   | Power Panic Z axis NOT lifted                     | Power Panic  | D3 Ax0c7f C1
+| ^           | ^       | ^                                     | 01h 1        | 01h                   | Power Panic Z axis lifted                         | ^            | ^
 
 |Address begin|Bit/Type | Name                                  | Valid values | Default/FactoryReset  | Description                                       |Gcode/Function| Debug code
 | :--:        | :--:    | :--:                                  | :--:         | :--:                  | :--:                                              | :--:         | :--:
@@ -621,9 +623,10 @@ static Sheets * const EEPROM_Sheets_base = (Sheets*)(EEPROM_SHEETS_BASE);
 #define EEPROM_KILL_PENDING_FLAG (EEPROM_KILL_MESSAGE-1) //uint8
 #define EEPROM_FILENAME_EXTENSION (EEPROM_KILL_PENDING_FLAG - 3) // 3 x char
 #define EEPROM_CUSTOM_MENDEL_NAME (EEPROM_FILENAME_EXTENSION-17) //char[17]
+#define EEPROM_UVLO_Z_LIFTED (EEPROM_CUSTOM_MENDEL_NAME-1) //bool
 
 //This is supposed to point to last item to allow EEPROM overrun check. Please update when adding new items.
-#define EEPROM_LAST_ITEM EEPROM_FILENAME_EXTENSION
+#define EEPROM_LAST_ITEM EEPROM_UVLO_Z_LIFTED
 // !!!!!
 // !!!!! this is end of EEPROM section ... all updates MUST BE inserted before this mark !!!!!
 // !!!!!

Firmware/power_panic.cpp

@@ -192,6 +192,9 @@ void uvlo_() {
 #endif
 
     // Finally store the "power outage" flag.
+    if (did_pause_print) {
+        eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO_Z_LIFTED, 1);
+    }
     eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO, PowerPanic::PENDING_RECOVERY);
 
     // Increment power failure counter
@@ -316,16 +319,16 @@ void recover_print(uint8_t automatic) {
     bool mbl_was_active = recover_machine_state_after_power_panic();
 
     // Undo PP Z Lift by setting current Z pos to + Z_PAUSE_LIFT
+    // With first PP or Pause + PP the Z has been already lift.
     // After a reboot the printer doesn't know the Z height and we have to set its previous value
-    if(eeprom_read_byte((uint8_t*)EEPROM_UVLO) == PowerPanic::PENDING_RECOVERY_RETRY) {
+    if(eeprom_read_byte((uint8_t*)EEPROM_UVLO_Z_LIFTED) == 1 ) {
         current_position[Z_AXIS] += Z_PAUSE_LIFT;
     }
 
     // Lift the print head ONCE plus Z_PAUSE_LIFT first to avoid collisions with oozed material with the print,
-    if(eeprom_read_byte((uint8_t*)EEPROM_UVLO) == PowerPanic::PENDING_RECOVERY)
+    if(eeprom_read_byte((uint8_t*)EEPROM_UVLO_Z_LIFTED) == 0) {
-    {
         enquecommandf_P(PSTR("G1 Z%.3f F800"), current_position[Z_AXIS] + Z_PAUSE_LIFT);
-        eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO, PowerPanic::PENDING_RECOVERY_RETRY);
+        eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO_Z_LIFTED, 1);
     }
 
     // Home X and Y axes. Homing just X and Y shall not touch the babystep and the world2machine
@@ -334,7 +337,10 @@ void recover_print(uint8_t automatic) {
     // Set the target bed and nozzle temperatures and wait.
     enquecommandf_P(PSTR("M104 S%d"), target_temperature[active_extruder]);
     enquecommandf_P(PSTR("M140 S%d"), target_temperature_bed);
-    enquecommandf_P(PSTR("M109 S%d"), target_temperature[active_extruder]);
+    //No need to wait for hotend heatup while host printing, as print will pause and wait for host.
+    if (eeprom_read_byte((uint8_t*)EEPROM_UVLO_PRINT_TYPE) == PowerPanic::PRINT_TYPE_SD) {
+        enquecommandf_P(PSTR("M109 S%d"), target_temperature[active_extruder]);
+    }
     enquecommand_P(MSG_M83); //E axis relative mode
 
     // If not automatically recoreverd (long power loss)
@@ -488,4 +494,9 @@ void restore_print_from_eeprom(bool mbl_was_active) {
     enquecommand_P(PSTR("G4 S0"));
     enquecommand_P(PSTR("PRUSA uvlo"));
 }
+
+void reset_uvlo() {
+    eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO, PowerPanic::NO_PENDING_RECOVERY);
+    eeprom_update_byte_notify((uint8_t*)EEPROM_UVLO_Z_LIFTED, 0);
+}
 #endif //UVLO_SUPPORT

Firmware/power_panic.h

@@ -18,3 +18,4 @@ enum PrintType : uint8_t {
 void uvlo_();
 void recover_print(uint8_t automatic); 
 void setup_uvlo_interrupt();
+void reset_uvlo();