EEPROM Settings

See https://github.com/MarlinFirmware/Marlin/wiki/EEPROM

Values are stored in EEPROM and will be maintained upon power down of Arduino. But EEPROM works only if enabled in Marlin?

EEPROM GCodes

• M500 Store current settings in EEPROM for the next startup or M501.
• M501 Read all parameters from EEPROM. (Or, undo changes.)
• M502 Reset current settings to defaults, as set in Configurations.h. (Follow with M500 to reset the EEPROM too.)
• M503 Print the current settings – Not the settings stored in EEPROM.