So I have a program that looks up the baud rate in EEPROM to use with Serial.begin()
With a known good Mega2560 R3 board, I uploaded the aforementioned sketch.
The sketch seemed to hang afterwards for a minute or two and then proceeded to run.
Serial connection doesn’t work (as expected at this point due to now known baud rate bug), but avrdude still gets a response.
Try to upload a new sketch - half way through upload it stops, never finishes.
Board is now a brick.
I’ve done this twice now, two separate boards now totally non-responsive, and can’t even burn a new bootloader with a USBasp programmer (avrdude: no response).
With a third board I was able to modify the sketch to directly set the baud rate and then inspect the value being previously applied and discovered it was 0.
I’m not willing to try a test case with just a “Serial.begin(0);”, I’m running out of boards right now!
Somehow that seems to make things really unhappy though.
No idea if this affects other processors/boards
TEST THIS AT YOUR OWN RISK!