LightInk

E-Ink watch that can run solely on solar power

9 votes·1 comment·May 1, 2026

About

An open-source, solar-powered E-Ink smartwatch. By re-implementing SPI in the ESP32's RTC wake stub and using a low-quiescent buck-boost converter, it reduces active boot time to under 1ms, delivering up to 10 months of battery life on a 100mAh charge.