I have a Prop board that homes a motor on power up and initializes the Rotary Encoder obj to zero. In cases of power outage or any number of reasons the main board could reset(error lockup, power outage, etc) I want to create a method to avoid rehoming if it has already been homed. So I'm thinking of adding a second Prop that has a battery and it can survive running at 80Meg for around a week. The concept is that the main board can offload the encoder position to the second Prop either at some frequency and on errors so that when the main board boots up, it can check the other Prop and receive that last known encoder position. I have 5V and 3v3 on the main board. There is space for batteries ( several D size or 9V types) but not a large 6V battery. I'd like this to be maintenance free for life(10years+). Any suggestions?
Edit. This is flawed from the start. If there is no power the motors can be moved and the encoder pos is lost. This would require the encoder to be powered and constantly tracking any changes. Maybe that’s an option. Run the encoder power from the second prop board from the battery/regulator at 5v. Parallel the encoder AB to the main board. On boot up the main board can read the encoder position active in the second board and update the position.