The PCBs arrived from @oshpark today (I can't thank them enough for all the help I'm getting from them, including the coupons and fast shipping), so time to assemble the next hardware version. This time there were no surprises, the board seems to work.

This new version has the buttons spaced a bit farther apart from each other, which makes assembly much easier. It also has an audio amplifier and a tiny speaker. Since I'm still waiting for the 4x4mm speakers to arrive, I used a bigger SMD speaker for now for tests, and it's pretty loud! The small speaker will probably be much quieter, but I think it will still be good enough.

I still need to connect the battery and test the charging circuit, but I don't expect much trouble there — the first version has that working well.