In the day, it's a bunch of mirrored discs with Burning Man's 10 Principles.
Unlike goggles I had made before, a belt has 360 degree visibility. The code incidentally is the same I used for my goggles, with just some
#defines the the bits that are different. It has two controls: brightness and pattern-select. The mode can select specific patterns, or cycle between various patterns. It's driven by a Teensy LC, and powered by a 3S LiPo pack connected to a buck converter / BEC to drop it to 5v. 5Ah lasts a full night.
The only clip I have of it in use at BRC 2017:
I wonder if I might be even more interesting if had etched the symbols on the mirror side so they would glow more and be reflected themselves.