Max, when I read your message I was unable to test your idea. But I thought: how come upgrading platformIO would solve the board’s port invisibility on 2 different unrelated computers, one of them having no development tool installed beside a port monitor and the ability to list visible serial ports.
Well…
It worked. I did the upgrade. Obviously right after the upgrade the board was still invisible (it was running a blink sketch). I put the board in bootloader mode, reupload my blink, do a pio device list, and … the board was now listed! pio device monitor also shows the expected output in the terminal.
As much as I’m really grateful for your solution and relieved that the problem is solved, I would like to understand what happened!
Opened questions (to myself and anyone else):
- Why did the board stopped being visible on any computer’s serial port and as reported above: did platformio caused the issue (the way it uploaded code or what it actually uploaded on the board), or is it specific to the nrf52840, or to the adafruit carrier board for that processor?
- How come a one line change in platformio core aimed at speeding up the device port finder could make the board be visible again as a serial port?