I currently plan to try something similar. (Stepper motor and on the shaft a magnet and on the PCB on the back of the stepper a sensor that tracks the position of the stepper. That PCB should contain everything, be attached at the end of the stepper and have only one (ethernet) cable. Data over UDP, power over passive PoE.)
Calibration (planed):
- Initial (stored in flash): slowly rotate once from left to right and back to get full “travel”.
- Each start: let the operator turn the wheels once from one side to the other, if same travel reported good to go (and know our zero which is in the middle ± steer zero adjust)
- While driving: minimal adjustments according to the deviation from guidance line
- At sharp turns (set aog to allow slightly tighter turns than possible) use the endstop for recalibration.