feature: add support for Arduino uno r4

[dndeus]

Does this work with arduino uno r4??

I'm keep getting

Error: programmer is not responding
Warning: attempt 1 of 10: not in sync: resp=0x00

[deadprogram]

Please see #4265

[dndeus]

Thanks for the update, I noticed you made a commit!!

I guess it's WIP?! it's not merge to main yet I assume

Thank you for your efforts!

[deadprogram]

I just updated the branch but there is still quite a bit of work needed to make it functional.

[dndeus]

cool, thanks for the update!