Hi James,

A few years ago, I was where you are now, looking at how to update the AA2TX approach. After a lot of digging around, I discovered a project named SAEBRTrack by Mark Hammond, N8MH, and Gene Brigman, KC4SA. They built a controller for a pair of Orbit 360 rotators, using a BASIC Stamp to provide an EasyComm interface to it.

https://sites.google.com/site/marklhammond/saebrtrack

Starting from that, I came up with something that uses an Arduino (Nano Every) as the controller, along with a 4-relay board from eBay. I wrote my own EasyComm code for the Arduino, tested with Gpredict and HamLib. I got as far as "proof of concept", which is to say that I got things working, but both hardware and software never quite got finished, since I got distracted by other things and never quite seemed to get back to it.

This is absolutely a doable and fun project. While I'm sure something could still be done with the original AA2TX digital pot approach, I think borrowing from the SAEBRTrack approach will result in a more complete solution.

By the way, Joe, you might be surprised at how frequently Orbit 360 rotators come up on eBay!

Martin.
KD6YAM