One of the greatest features of Adept's RP2040-based board is a very convenient and simple method of firmware flashing. If two contact points on PCB are shorted before plugging device in, it will be recognized by operating system as a removable disk drive. Binary file containing the new firmware is then just copied to that drive: that's all!
In order to access these "magic contacts", the Adept case needs to be opened. To make the procedure even more easy, I've soldered micro-sized switch to the bottom side of PCB, drilled hole in the base, and added little push button.
Now there's no need to disassemble the trackball for updating the code in case of failure anymore. Several variants of the firmvare are currently available to download from Ploopy's repository: https://github.com/ploopyco/adept-track ... /firmwares
The same functionality can be included in firmware routine, to be invoked by holding some button during connection (in case of Adept, it's a left mouse button), but of course it works only when the firmware is fully functional. If not - mentioned contacts are the only way to reprogram the board.