so ive been messing around with an old Yaesu G-450A rotator that i picked up at a hamfest last spring and the controller is functional but kind of a pain to use especially when im trying to track satellites and also do other stuff at the same time. someone at the club mentioned that people have been using arduinos to automate rotators and interface them with software like PstRotator or even just write their own logic and honestly that got me down a rabbit hole for like two weekends straight.

i ended up buying an Arduino Mega (probably overkill but i had a coupon) and a bunch of motor driver modules and ive been reading through other peoples projects online but a lot of them are half documented and you kind of have to guess at the wiring. what i really want is for the thing to be able to receive AZ/EL commands over serial from my computer and then drive the rotator to that position and report back. seems doable but the analog feedback from the rotator pot is giving me weird readings and im not sure if its a voltage divider issue or if my ADC just needs more averaging or what.

anyone done something similar with this specific rotator or honestly any rotator, id love to know what approach worked for you. also curious if anyone has tied this into a Raspberry Pi instead, i have a Pi 4 sitting in a drawer doing nothing and wondered if thats a better approach for the serial interface side of things.

yeah ive done almost exactly this with a G-800 which is a bit beefier but the feedback pot circuit is basically the same idea. the wobbly ADC readings are almost certainly noise on the analog line — those pots are sitting in an environment with a motor running nearby and the shielding inside those rotators is not great. what helped me was adding a small 100nF ceramic cap right across the wiper and ground at the arduino input pin, and then doing a rolling average of maybe 16 samples in code before you do anything with the value. made a huge difference.

for the serial command interface i just used the Hamlib rotctld protocol since PstRotator and most other programs already speak it, so that saved me writing any of that parsing logic myself. the arduino just listens for the set_pos and get_pos commands and does its thing. pretty clean once you get it going.

and yeah tying a Pi in is a good move if you want to run rotctld as a daemon and have the arduino just handle the low level motor control. that separation of concerns makes it easier to debug too. just use a proper 3.3v to 5v level shifter on the serial lines if you go that route, ive seen people fry pi GPIO pins skipping that step.

cant really help with the rotator specific stuff but i will say the Pi 4 in the drawer thing resonates deeply with me, i have three of them doing nothing and keep telling myself ill make them into something useful. one of them is technically running a WSJT-X remote setup but the other two are just sitting there judging me.

the arduino plus pi combo is actually a really solid architecture for this kind of thing from what ive seen. arduino handles anything that needs to be real time or PWM or whatever and the pi handles the network stuff and the UI. i built a little automated antenna switch with that setup for my HF station and its been running for like eight months without me touching it which is either a good sign or means ive completely forgotten how it works.