So I've been messing around with automating my antenna rotator for the past few months and finally got something semi-functional. Started with a Raspberry Pi 4 but honestly the Arduino Mega ended up being way more appropriate for the actual motor control side, Pi is sitting upstream handling the logging and the web interface I threw together.

Basic setup is the Arduino reading a pot on the rotator shaft for position feedback, then driving a relay board to handle the direction and a PWM signal going into a motor controller for speed. The pot side took forever to dial in because cheap pots are noisy as anything and I kept getting jitter that would make the antenna hunt back and forth. Ended up adding a small cap across the wiper and ground which helped a lot, then just did some software averaging on the ADC readings.

The Pi runs rotctld so it integrates with WSJT-X and a few other things automatically which is the part that actually feels like magic when it works. Click a callsign on the band map and the antenna just... moves there. Probably took me 40 hours total to get to this point which is maybe not the most efficient use of my time but here we are.

Anyone else doing anything similar or have thoughts on whether I should just have bought a commercial controller to begin with. I know the Yaesu interfaces exist but where's the fun in that.

yeah I went down almost exactly this same path about two years ago, except I tried to do everything on the Pi and regretted it pretty quickly. the real time stuff just doesnt play nice on a linux system without a lot of pain, latency was all over the place and the motor would overshoot constantly. splitting it up like you did with the Arduino handling the low level control is definitely the right call.

one thing I added that helped a lot was a second pot geared down further for coarse position and using the original for fine — kind of like a vernier deal. overkill probably but it got my pointing accuracy down to about 2 degrees which is good enough for my 2m yagi. also if you havent looked at it already there's a guy on github who did a pretty clean rotctld daemon implementation that talks to Arduino directly over serial, saved me writing a bunch of glue code.

commercial controller wouldve cost you what, 150 bucks maybe, but you wouldnt have learned any of this so I think the 40 hours is kind of beside the point honestly. I've got a G-450A that's been sitting in the shack for two years because the controller board fried and I just havent wanted to deal with sourcing the replacement. maybe I should just do what you did instead of waiting on a part.