I have a Arduino Uno Rev 3, and uses a macbook Pro running BigSur.
Here's the issue:
I upload a sketch (blink) and its works fine. I modify the sketch, reupload, still fine.
Then I disconnect the USB, and reconnects it.
Whatever sketch I try to upload, I get a "stk500_recv(): programmer is not responding".
I can disconnect/reconnect, reboot the mac, restart the IDE, press the reset button, nothing.
Then I reset the Arduino by connecting the reset and the GND, use dfu-programmer to erase, flash (with this one: ArduinoCore-avr/Arduino-usbserial-atmega16u2-Uno-Rev3.hex at master · arduino/ArduinoCore-avr · GitHub) and reset. Unplug, replug. And tada, it works.
If I unplug and replug the USB after an upload, the whole cycle starts again.
Could some hero save me?