Freedom units are stupid and harmful, so for the return of the #The Square Inch Project I decided to try and make a square centimeter project. I wanted something simple yet useful, so I decided to go with an electronic D6 die. You know, seven LEDs that randomly show numbers from 1 to 6. Since most of the LEDs actually come in pairs, I only actually need three GPIO pins (tri-stating the middle LED). That means I can use an ATtiny9 chip that I have lying around.
I will use a watch battery, and a single button that doubles as power button. Basically every time you press it, the device switches on, loads the seed, generates random number, displays it, and hangs.