A Reddit creator going by the handle PickentCode has constructed a standalone compact computer that operates without a traditional battery or external electrical wiring. The self-sustaining system generates its required operational power through an integrated micro-Stirling engine and generator that convert temperature differentials into usable electricity.

The builder designed a custom wooden enclosure featuring laser-engraved schematics of inventor Robert Stirling, utilizing 3D-printed components for structural assembly. Internal specifications include a 2.42-inch monochrome display, a 16-key tactile keypad, and an ESP32 C3 microcontroller. Voltage stabilization is maintained using dedicated capacitors and an embedded voltmeter.

To accommodate the engine's modest output of roughly 150 milliwatts, the creator disabled power-intensive Wi-Fi and Bluetooth modules while throttling processor clock speeds and screen brightness. Despite these efficiency constraints, the computing rig remains fully operational, supporting system execution for retro titles like Tetris and Snake alongside custom software code.

The project highlights viable applications for micro-scale thermodynamic energy harvesting, showcasing alternative power solutions for low-draw computing hardware.