Yet Another WLED PCB

What is WLED

WLED is a project for controlling LED's over WiFi that I have a lot of experience with. I have made Rust libraries for interfacing with these over their HTTP API, and DDP protocol over UDP. I haven't made any PR's to the core project though, as it does everything I want it to. I did, however, contribute to their docs which is what I used as the framework for this site.

Another WLED board??

WLED is known for having like 50 different boards that can run it, but I was unable to find one with the specific features I needed at a reasonable price. I needed mine to have multiple outputs, be fully waterproof, an extra relay, and most importantly the ability to easily change the impedance matching resistor, as my LED setup uses many extensions of arbitrary characteristic impedances.

Impedance matching

I really didn't think I would need to do any impedance matching as my runs are only a couple meters, but I was observing glitches in the lights and when I looked with an oscilloscope the reflections were pretty bad.

Those are measured on different lines, hence the offset, but there are still vey obvious ripples.

The schematic

I haven't done any formal EE training or education, so most of it was put together with example applications from datasheets and the most basic of principles. I wanted the board to be able to be powered from 5v or 12v and have options for which features to populate. The optional parts are in the dashed line zones, and include the 12v support, extra relay, and level shifters.

The PCB

The PCB wasn't too hard, there is only one routing consideration which is the USB data lines, but the rest was trivially easy. I did also remove the ground plane around the extra relay because I plan on using it with wall power.

The enclosure