so ive been messing around with an arduino uno for the past few weeks trying to get it to control my old CDE Ham-M rotator and honestly its been a bit of a rabbit hole. the rotator controller itself still works fine but the pot feedback is all over the place and i thought hey why not just replace the whole control box logic with something i can actually program.

right now ive got the arduino reading the pot voltage through analog pin A0 and its doing okay but im getting like plus or minus 8 degrees of wobble which is way more than id like. not sure if thats a grounding issue or just the pot being worn out after 30 years. im running 5v to the pot and reading it through a voltage divider but maybe i should be using a 10-turn pot as a replacement instead of the original.

anyway the bigger question is whether anyone has gone the raspberry pi route instead for something like this — i was thinking a Pi would let me just run a web interface to control it from the shack PC or even remotely which would be pretty sweet for when im doing some satellite work. but then again its probably overkill just for turning an antenna. thoughts?

yeah the pot wobble is almost certainly the old pot being worn, those things get dirty and resistive in weird spots after decades of use. i replaced mine with a 10k 10-turn precision pot and the difference was night and day, way more stable readings. also worth throwing a small cap like 0.1uf across your analog input to ground, helps filter out noise pickup on those long leads going to the rotator.

on the pi vs arduino question — i actually run both. arduino handles the low level stuff like reading position and driving the motor relay, and i have it talking to a pi zero w over serial. the pi runs hamlib and rotctld so any logging software or satellite tracker that supports hamlib just connects to it like a normal rotator. its a bit more wiring but honestly once its running you basically forget its there. been solid for about 8 months now tracking LEO birds.

dont overthink the pi vs arduino thing too much, i spent like three weeks going back and forth on that for my own rotator project and honestly just pick one and go. i went pure raspberry pi, python script, little motor driver board off amazon, done. the web interface thing is totally doable, flask makes it pretty easy even if you dont know much python. the latency isnt really a problem for antenna pointing unless your doing something really fast moving which a ham-m aint gonna do anyway lol