I have recently been working on a bare metal project on a raspberry pi. I have been using a uart to usb cable to for logging, which has been able to send messages to my computer. Recently however, it has stopped working.
I tested the cable using an Arduino and it works.
I installed a fresh version of raspbian on an sd card and tried to use uart from that. When I booted with the cable plugged in, or plugged the cable in, it would either not power on or immediately power off. To further debug, I plugged in an led to the gpio pins and turned in on and off. The pins 14 and 15 (UART TX and RX), however did not work with the led.
At this point, my conclusion is that the UART pins are fried. Is this a valid conclusion and if not, how should I further debug?