Save/restore hotend temperatures above 255C in PowerPanic

Use 2 bytes to store extruder temperature during UVLO.

Re-use the storage of EEPROM_UVLO_TINY_Z_MICROSTEPS which has been freed
by previous changes.

Fixes #2303

Firmware/Marlin_main.cpp

@@ -10505,7 +10505,7 @@ void uvlo_()
 
     // Stop all heaters
     uint8_t saved_target_temperature_bed = target_temperature_bed;
-    uint8_t saved_target_temperature_ext = target_temperature[active_extruder];
+    uint16_t saved_target_temperature_ext = target_temperature[active_extruder];
     setAllTargetHotends(0);
     setTargetBed(0);
 
@@ -10605,7 +10605,7 @@ void uvlo_()
     // Store the current feed rate, temperatures, fan speed and extruder multipliers (flow rates)
 	eeprom_update_word((uint16_t*)EEPROM_UVLO_FEEDRATE, feedrate_bckp);
     eeprom_update_word((uint16_t*)EEPROM_UVLO_FEEDMULTIPLY, feedmultiply);
-    eeprom_update_byte((uint8_t*)EEPROM_UVLO_TARGET_HOTEND, saved_target_temperature_ext);
+    eeprom_update_word((uint16_t*)EEPROM_UVLO_TARGET_HOTEND, saved_target_temperature_ext);
     eeprom_update_byte((uint8_t*)EEPROM_UVLO_TARGET_BED, saved_target_temperature_bed);
     eeprom_update_byte((uint8_t*)EEPROM_UVLO_FAN_SPEED, fanSpeed);
 	eeprom_update_float((float*)(EEPROM_EXTRUDER_MULTIPLIER_0), extruder_multiplier[0]);
@@ -10871,7 +10871,7 @@ bool recover_machine_state_after_power_panic()
   enable_z();
 
   // 7) Recover the target temperatures.
-  target_temperature[active_extruder] = eeprom_read_byte((uint8_t*)EEPROM_UVLO_TARGET_HOTEND);
+  target_temperature[active_extruder] = eeprom_read_word((uint16_t*)EEPROM_UVLO_TARGET_HOTEND);
   target_temperature_bed = eeprom_read_byte((uint8_t*)EEPROM_UVLO_TARGET_BED);
 
   // 8) Recover extruder multipilers

Firmware/eeprom.h

@@ -72,8 +72,8 @@ static_assert(sizeof(Sheets) == EEPROM_SHEETS_SIZEOF, "Sizeof(Sheets) is not EEP
 #define EEPROM_FILENAME (EEPROM_UVLO_CURRENT_POSITION - 8) //8chars to store filename without extension
 #define EEPROM_FILE_POSITION (EEPROM_FILENAME - 4) //32 bit for uint32_t file position 
 #define EEPROM_UVLO_CURRENT_POSITION_Z	(EEPROM_FILE_POSITION - 4) //float for current position in Z
-#define EEPROM_UVLO_TARGET_HOTEND		(EEPROM_UVLO_CURRENT_POSITION_Z - 1)
-#define EEPROM_UVLO_TARGET_BED			(EEPROM_UVLO_TARGET_HOTEND - 1)
+#define EEPROM_UVLO_UNUSED_001		(EEPROM_UVLO_CURRENT_POSITION_Z - 1) // uint8_t (unused)
+#define EEPROM_UVLO_TARGET_BED			(EEPROM_UVLO_UNUSED_001 - 1)
 #define EEPROM_UVLO_FEEDRATE			(EEPROM_UVLO_TARGET_BED - 2) //uint16_t
 #define EEPROM_UVLO_FAN_SPEED			(EEPROM_UVLO_FEEDRATE - 1) 
 #define EEPROM_FAN_CHECK_ENABLED		(EEPROM_UVLO_FAN_SPEED - 1)
@@ -165,13 +165,11 @@ static_assert(sizeof(Sheets) == EEPROM_SHEETS_SIZEOF, "Sizeof(Sheets) is not EEP
 #define EEPROM_EXTRUDER_MULTIPLIER_2 (EEPROM_EXTRUDER_MULTIPLIER_1 - 4)                        //float
 #define EEPROM_EXTRUDEMULTIPLY (EEPROM_EXTRUDER_MULTIPLIER_2 - 2)                              // uint16
 
-//
 #define EEPROM_UVLO_TINY_CURRENT_POSITION_Z (EEPROM_EXTRUDEMULTIPLY-4) // float
-#define EEPROM_UVLO_TINY_Z_MICROSTEPS (EEPROM_UVLO_TINY_CURRENT_POSITION_Z-2) // uint16 (unused)
+#define EEPROM_UVLO_TARGET_HOTEND (EEPROM_UVLO_TINY_CURRENT_POSITION_Z-2) // uint16
 
 // Sound Mode
-//#define EEPROM_SOUND_MODE (EEPROM_EXTRUDEMULTIPLY-1) // uint8
-#define EEPROM_SOUND_MODE (EEPROM_UVLO_TINY_Z_MICROSTEPS-1) // uint8
+#define EEPROM_SOUND_MODE (EEPROM_UVLO_TARGET_HOTEND-1) // uint8
 #define EEPROM_AUTO_DEPLETE (EEPROM_SOUND_MODE-1) //bool
 
 #define EEPROM_FSENS_OQ_MEASS_ENABLED (EEPROM_AUTO_DEPLETE - 1) //bool