After recently binging all of The Dragon Prince on Netflix, I decided to build a replica of the Key of Aravos, a magic device from the show. But rather than just build a static prop, I decided to build a fully functional version, or at least as much as I could in a world lacking magic.
The Cube uses a Neopixel ring and jewel inside each face, set behind a translucent opening for the rune in each face. An accelerometer and capsense board are used to determine which side to light up. The whole thing is controlled by a Trinket M0 running CircuitPython, and a 1000ah LiPoly battery powers it.
Full write-up is here: