Reclaim Your Privacy with This DIY E Ink Smartwatch

Modern smartwatches are packed with features, compact, and stylish. They are also typically black boxes that leave no room for modification. This fact also means that you cannot be certain if these devices are respecting your privacy, or if they are transmitting all manner of sensitive data to an unknown cloud server.

If you are technically inclined, you can get around these issues by building your own smartwatch. Small, inexpensive components that are ideally suited for this application are easy enough to come by these days. However, unless you have wizard-level skills, the result isn’t going to look anywhere near as good as a commercial watch.

Instructables user Selbyc isn’t worried about appearances, and happily embraces the DIY look. Because of this, he decided to build his own hackable, privacy-protecting E Ink smartwatch. It might get him some funny looks in public, but it is the exact smartwatch that Selbyc wants. And if you would like your own, step-by-step instructions have been provided to help you make that happen.

The project was designed around the Seeed Studio nRF52840 Sense, which was paired with a Waveshare 2.9-inch flexible E Ink display. E Ink offers excellent readability in bright sunlight and consumes very little power, enabling the watch to run for nearly a week on a single charge. Unlike traditional smartwatches that constantly demand attention, this one is designed to stay out of the way and simply provide essential information.

The project began as a breadboard prototype used to validate the core concept. Early experiments confirmed that the display could be driven reliably, sensors behaved as expected, and power consumption was low enough to make the idea practical. Encouraged by these results, Selbyc moved on to more ambitious designs involving flexible PCBs and modular sensor layouts.

However, the flexible era proved to be the most challenging phase. Despite their name, flexible E Ink displays turned out to be extremely fragile, especially around the connector area. Combined with delicate PCB traces that failed under repeated bending, the design struggled to survive real-world use. After multiple broken components — and plenty of frustration — it became clear that a fully flexible smartwatch was not yet viable.

To get things working reliably, Selbyc added a rigid frame to the build. Initially improvised from a cheap bracelet, and later refined using a heat-shaped plastic ruler lined with pleather, the new structure protected the display and provided the durability needed for daily wear.

Though still a work-in-progress, the watch is now wearable and robust. Future plans include introducing more sensors, improving power management, and developing a more refined rigid-flex PCB design.