I'm in the process of restoring an old Onan emergency generator to working order as well as adding an arduino (mega w/ etherent) to it to control remote start and stop operations as well as reporting oil pressure and water temperature of the engine. The unit has an hours meter installed on the control panel that I would like to "mirror" on the arduino.
When the generator is running one of the digital inputs goes HIGH. I want the accrued hours to be stored in non volatile memory so it can survive a reboot and updated once the generator shuts down. Any ideas?