What's the size of a credit card and can run CircuitPython, MakeCode Arcade or Arduino? That's right, it's the Adafruit PyBadge! We wanted to see how much we could cram into a ​3 3⁄8 × ​2 1⁄8 inch rounded rectangle, to make an all-in-one dev board with a lot of possibilities, and this is what we came up with.