RockPro64 UPS for in car use

[ender_saved]

Hey bro. I wrote about power management in the other thread you posted.
You need to find out if RockPro64 has some kind of pwr_off pin which can be shorted with another pin to imitate power button. My Odroid XU4 has a dedicated PWR_OFF pin which can be shorted with any of 1.8-5v pins to initiate shutdown process. So I simply connected my Mini-Box DC-DC 200 board to these pins. What the Mini-Box board does is it detects ignition switching and shortens the pins on my Odroid XU4 and waits around 40 secs to make sure the board shuts down. After 40 seconds it completely cuts the power from car battery.
When you turn the ignition on the Odroid XU4 gets power automatically and starts. The board from Mini-Box also has protection so you don't fry your single board computer.

If RockPro64 has similar pins you can use it will be pretty easy (still not very cheap) to do that.






I added header pins to the locations circled and use a standard momentary switch.  The OS you use can decide what the response is.  Hope this helps