Maker Builds Mechanical TV Using Raspberry Pi Pico, 5 LEDs, and a Spinning Disk

Maker James Brown, known online as 'Ancient,' has recreated a 1920s mechanical television concept using modern, low-cost components including a Raspberry Pi Pico, a stepper motor, and five LEDs. The device, called the Scanwheel, works by spinning a disk drilled with 20 pin holes in front of fixed LEDs, with the Pico precisely timing each LED blink to render one row of pixels per hole. This persistence-of-vision technique fuses the rapidly blinking rows into a coherent 20-pixel-tall image, with horizontal resolution determined by spin speed and GPIO modulation rate. Four of the five LEDs are white, while a single RGB LED in the center provides the only color channel. The full build guide and video are available on Hackster, and the entire project costs less than a week's worth of lunches.