I discovered what caused my problem. I just connected the LED bar to the pins on the “right”, ie the range of pins [15…3]. And I set output mode on each of them. The culprit was this line of code: GPIO.set_mode(3, GPIO.MODE_OUTPUT)
Setting the UART0 port to OUTPUT caused my issue. Flashing the firmware again was the only solution after running this line of code once. So now I skipped pin 1 and 3 and don’t explicitly set the pin to output anymore.
This may sound logical for some people, but I cannot find information with which I can draw such a conclusion myself. I want to prevent similar mistakes in the future.
Can anyone explain why setting the UART0 pins to output may cause such issues?