For the latest designs of these gizmos, I have had custom printed circuit boards (PCBs) manufactured with surface mount components pre-soldered by the factory. This turns out to be surprisingly affordable: just a few dollars per board (including shipping) and a 5-day turnaround from China.

The project uses an ESP32 DevKit-v1 processor board, with gobs of flash and RAM, plus WiFi, Bluetooth, and USB all built-in. The custom PCB mates with that and provides the interfacing electronics to connect with a Celestron AUX port, as well as to accessories like the GPS receiver and Nunchuck controller.