LightInk
E-Ink watch that can run solely on solar power
4 followers
E-Ink watch that can run solely on solar power
4 followers
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.
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Hi everyone!
LightInk is a great example of what happens when a constraint is pushed to the extreme.
The project pushes the chip into an ultra-low-power regime: wake stub execution, custom SPI in RTC memory, sub-millisecond display updates, then straight back to deep sleep. That is just a genius engineering move you only find when the constraint is taken seriously enough.
And that is what makes the product logic interesting. Once you design around E-Ink, solar power, power-gated features, and obsessive energy budgeting, the watch becomes a very different kind of wearable: a 90s solar digital watch rebuilt with ESP32, E-Ink, LoRa, GPS, touch, and open-source hardware.
Not a polished consumer device yet, but a very fun reminder that extreme constraints can produce much more interesting product directions.