This case holds an Adafruit Circuit Playground () and Ares Rescue power bank () to power it via USB. It is intended to be used for demonstrations using the onboard sensors and LEDs (should be printed with a translucent plastic). First, insert the Circuit Playground with the USB connector facing the opening (down, in the printing orientation), then insert the battery to lock it in place. The battery has a built-in USB cable that you will have to pull out of its slot before inserting the battery. Designed for my Hacker Calculus project: