This is a custom AdaFruit Neopixel Jewel Ring (7 LEDs) housing for a small DIY electronics project as electric light in a lantern for Kindergarten. A bare-bone ATTiny45 microcontroller determines the acceleration of the lantern and calculates the hue and brightness of the LEDs according to the direction of swinging.
The files includes two different lids. One was an experiment to create a procedural sculpture using OpenSCAD to carry the light of the seven LEDs up to the top. When I printed it with transparent PLA, still much of the light was absorbed, so I used a simpler lid instead.
The Arduino sketch using LSM303 library, FastLED and UWI I2C is available on demand. It just barely fits the 4KB ROM and 256 bytes RAM of the microcontroller. Basically, it uses two pins for I2C communication with the LSM303 sensor, one pin to power the LSM303 sensor (due to a power-good bug on startup), one wire for the as data line for the WS2812 LEDs. A few flying wires are used inside the housing
I made other advanced lanterns the following year, mostly with Teensy and bigger microprocessors, more LEDs etc.
This one was the smallest one that was the most fun making.