Highly recommend the Arduino one on sourceforge.
That author has several Arduino based astronomy products.
https://sourceforge.net/u/brownrb/profile/
If you search a bit, I think there are some more gadgets he’s built that aren’t on that list. His documentation is incredible for an open source device.
I’ve just built version 2 of his focuser after I broke my Microtouch controller (long story). A replacement microtouch was going to cost me $700 landed in Australia. The Arduino based one was less than a tenth of that. I managed to get it working with the microtouch motor after some trial and error on the wiring.
Used the new controller on the weekend - perfect.
DT