Ever wished your D20 rolls came with a dramatic light-up reveal? PiShop built exactly that, a physical electronic dice roller using a Raspberry Pi Pico and an 8×8 LED matrix driven by a MAX7219. Each result from 1 to 20 gets its own handcrafted bitmap, a pixel-font number rendered inside a rounded dice border, crisp, readable at arm’s length, and oddly satisfying to watch. The build is beginner-to-intermediate friendly, with a short parts list and everything breadboard-compatible. The MAX7219 communicates with the Pico over SPI, and the buttons rely on the Pico’s built-in pull-up resistors, no external resistors needed.

The real magic is in the roll animation: 20 frames of random results flash across the display, with the delay between frames starting at 55ms and increasing by 11ms each frame, mimicking a die decelerating to a stop. The final result is locked in before the animation even begins, so the outcome is always fair — and a brief blank flash before the reveal adds a satisfying moment of suspense.

Written in MicroPython and thoroughly documented, it’s a perfect weekend project for tabletop fans and makers alike.