Hacking with Claude on a $27 Smart Watch

The author used Claude via OpenCode to build a custom Casio-style watch face for a PineTime smartwatch in a few hours of iterative AI-assisted firmware work. Static display elements were baked into a fullscreen background image, leaving only dynamic components to render at runtime, which reduced rendering complexity on the constrained device. Transfer of the 240x240 image over Bluetooth took roughly 10 minutes and caused 1 to 2 second refresh delays, but the prototype was considered functional and the code was published to GitHub.