I've been experimenting with designing simple carrier boards for Teensy and other microcontrollers, mainly to control Neopixel LEDs. The end goal is to have standalone, battery-powered diamonds that can be placed outdoors for nice ambient lighting at night.
Thanks to my abundance of Teensy microcontrollers, I began with designing and milling a few revs of a simple carrier board with my Othermill.
In order to boost the 3.7V from the LiPo battery to 5V for the LEDs and Teensy, I'm using a Powerboost from Adafruit. Here is the first prototype working:
Similar to my Light Box, I'm using heavy paper to prototype the position of the board and LEDs in the diamonds (which I did not make, but was gifted). A hole punch and cable ties also come in handy for quick prototyping!