Do you like 3D printing, mold making, industrial design, jewelry, and RGB LED’s? You’re in luck, then. I just finished this tutorial for Adafruit and think it’s well worth a look.
In this project, I attempted to make an Arduino powered device that was easy to use, easy to make, and self contained. Every 3d printed component can be done in a single build without support material. The ring has a battery, switch, and USB port. Once it’s together, all you need to charge or reprogram it is a USB Micro cable.