2023-10-14

Playing with a serious number of WS2812B RGB LEDs

I have done some fun stuff with LEDs, but now I have found some very small 1mmx1mm WS2812B LEDs, I decided to make a Stargate.

Well, the doctor said to rest, so this is my resting! I have spent a week on this - much of that waiting for slightly wrong 3D prints to print. 3D printing is always a massive time hog.

My first ideas was 210 LED, but then I went for a better design with 372 LEDs.

I have since revised the design to 507 LEDs!

The image shown here is the 372 LED design.

Needless to say, some C code was used to place the LEDs and caps and vias and tracks for this.

To my surprise the power usage is not that bad, all 372 LEDs on full white is 3.6A, including the ESP32. So can run off a suitable USB charger.

In practice, the Stargate dialling sequence does not go over 0.8A, so no problem.

As usual, all open source on my GitHub.

However, I did find that JLCPCB cannot cope with more than 400 designators on one line in a BOM file :-)

As for spinning, I could make a spinning effect using 117 LED rings, but I could not spin the actual glyphs - so as a compromise I illuminate the glyphs that are dialled in situ. I think it works quite well.

Of course, the challenge then was a 3D case for it. This was tricky - there are a lot of 3D models of stargates, some more easily printed than others, but I wanted one I could nicely slice in two and allow the PCB to be inserted. That proved more complex, so I designed one from scratch in OpenSCAD. It is simplified to be easy to 3D print, even though the whole thing is nearly 7 hours print time.

I also needed a reasonably neutral colour to allow the LEDs to show. I ended up using the ColorFabb Glowfill, which has the side effect that it glows in the dark.

Here is it dialling...

This is the latest 507 LED PCB design, the main change is an extra kawoosh ring that will be inside the 100mm gate ring. The idea is that this could then work with a mirror and half mirror perhaps to make a gate tunnel effect. I'll see when I make some more. It works out around £30 per board, shipped.

The extra tabs are not a space gate effect, honest, they are tooling holes and fiducials for production, and get snapped off.


That's a lot of LEDs

2 comments:

  1. Have you seen (or perhaps even bought?) a Bambulabs carbon x1? It is mind bendingly fast at turning out prints, and as close to a printing appliance I've come across yet. Patrick

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