Thanks @IanF for sharing your code, I'll merge that when I find a moment. As far as I've seen there is no actual difference in the library itself (reminds me I probably already merged ntruchsess work back in the time). So actually, the library is already compatible with that microcontroller? I'll add your sketch as another sample, if you're ok with that.
Yep, a logic analyzer is a requirement for this kind of work. I used a $30 second-hand USB oscilloscope for the task, not the best tool, but works.
Well, actually, I've made a few tests, and it appears all user accounts can already fork on this gitea server, even if the repository limit has been reached (i.e. forking is a special case that bypasses that limit).
@IanF until I find a more permanent solution, I've allowed you one repository creation, you should be able to fork on gitea, and then push your code from your local repository.