The Pomera DM30 is another option for anybody who wants something superficially very similar to OP's setup but without the DIY aspect. It's kind of expensive and only comes in a Japanese keyboard layout, but I love mine.
I link to this Pomera device from the repo, as well as Freewrite's one. I would have totally bought the Pomera if I could change keyboard layout. As I do most of my creative writing in French I absolutely need an AZERTY keyboard.
Thanks for this repo :)
I also writes in French, but decided to switch to Qwerty layout a while back to get access to a wide-range of nice keyboard. Very happy with this move.
I know this will not help you right now, but just saying you may not totally stuck to AZERTY forever.
