This post is in an update to my previous entry on creating an LED Matrix display. If you haven’t read it yet, go check it out.

I want to use my display as a wall clock when it isn’t playing movies or animations. Luckily, WLED is open source and is relatively easy to update and modify. I proceeded to add a 2D Analog Clock effect and created a pull request.

Naturally, I wanted to have some nice anti-aliased lines, so that was another thing to implement. Luckily, it’s not rocket science and Jack Bresenham already created algorithms to do exactly this. All it takes is just a little bit of typing and we’re good to go.

The display already connects to the internet and has an NTP client built in, so within a few seconds of applying power it has the clock correctly set. Hopefully it also has fixes for daylight savings.

My hope is that this effect will get added in as a standard effect. Since I’m just a new contributor to the repo I’m not sure how long that would take. In the mean time you can get a precompiled version here for the ESP32, or take a look at my 0.14.3 branch and roll your own. There seem to be some issues with the 0_15 branch, so it’s best to use the 0.14.3 version. That is what the precompiled version uses as well. The pull request is for the 0_15 branch which I’m sure will get fixed as the team is pretty responsive.