So I Almost Burned My Finger

I was trying to get the encoders to work, but in the process of reading data through USB serial, I got a mild shock

How Did This Happen?

To configure hall effect encoders, you need to give each wheel a good spin to determine how many “pulses” are detected by the Pico. The detection part is quite simple: whenever the wheel turns a certain amount, motor encoders A and B change state. This can be detected through an interrupt and then printed out (in the main loop, not the callback). However, in the process of printing it out, I touched the USB-C receptacle and felt it get extremely hot, and later realized that something got shorted somewhere.

Any Guesses Where?

Looking back at the situation, I had connected the battery and USB power from my laptop to the board at the same time, so something might have gone wrong there. Another thing that was going wrong was that the receptacle itself was coming off, so it could be that one of the pads, say +5V for instance, came in contact with like GND or smth, inducing shock if someone were to touch it.

Here’s an image from the timelapse right before I plugged the board into my laptop and fried it: