I just pulled my Bangle.js 2 back out to play with making a better reminder system for myself. It works better than any of the other open source watches I’ve had with my GrapheneOS phone. The hardware isn’t open source as far as I know, but their mobile app (fork of gadget bridge) is, as are all the apps that run on the watch, and (I think?) the watch OS.












I’ve always wondered if something like this would work:
Take a relatively short bit of wire, make a flat spiral at one end about the size of the button, tape that spiral to the button. Then take the other end of the wire hook it up to a relay with the other end attached to ground (or any big metal object probably). I would imagine then closing the relay is “touching” and opening the relay is “not touching”.
I have no idea if that would actually work, but it seems to me like it should. You just need something to interrupt the electric field above the “button”.