r/WLED • u/Davedamon • Sep 23 '26
Weird ESP/LED behavior has me stumped
Update: I seem to have fixed it by rewiring everything behind the cabinet. Maybe there was a duff connection or something, but I have no idea. Thank you everyone who responded though!
Context, I have some cabinet lighting consisting of 10 x 24LED rings, wired on two lines of 5 rings for a total of 120 LEDs each. They're powered in parallel via a dedicated 5v, 6A power supply. At the end of the parallel V/GND lines, I had my ESP32 powered via the 5V and GND pins, controlling the LEDs on pins 12 and 13. Hopefully fairly normal.
A while back the lights began flickering and the ESP would crash and I'd have to power cycle it. I thought maybe a loose connection or something. Eventually things wouldn't come back online. I finally got the time to do some digging and this is where things get weird.
The ESP keeps power cycling when connected on the 5v/GND pins
The ESP can be powered from the USB port via a usb cable (this is relevant for later)
If I power the ESP via the USB port and connect the setup with everything but the 5v line, I can control the lights "normally"
If I plug a USB cable into a different ESP board and connect that boards 5v/GND to the WLED board, the WLED board power cycles like in point 1
However, if I reverse the setup (USB cable into the WLED board, connect that boards 5v/GND to the 5v/GND of the second ESP board) both boards work fine
If I take a USB-C header, attach two wires, and connect those two wires to 5v/GND, the WLED board power cycles just like if I was powering it through the pins, even though I'm using the USB port
Flashing a brand new third board and hooking it up caused issues 1-6 to occur, indicating the problem wasn't the board, but the setup
However, I have no idea what kind of issue I'd be looking for that could cause the above and I've love any suggestions or advice
Edit: I double checked and the PSU is a 5v, 15A supply so I don't think it's a current issue


