Tiny $30 DIY e-ink reader is smaller than an AirPods case with 2-week battery

Paul Lagier just updated his project for the world’s smallest e-reader - he has now moved from a rough prototype to a more durable iteration. Version two is just a viral response to his original build, which was launched just over a month ago as a minimalist way to reclaim time spent on mobile gaming.

The first version of the reader (see below) was built around an ESP32 microcontroller (curr. $16.79 on Amazon) and a 2.9-inch monochrome e-ink display. While functional, that prototype went through assembly issues; the 3D-printed case relied on tiny plastic pins that were difficult for many hobbyists to produce reliably. It also suffered from inefficient memory management, wasting most of the board’s 8 MB flash storage and leaving only 1.5 MB - only enough for about two books for the user.

The new version does away with these issues by switching to a screw-down case design using M2 threaded inserts. This makes the device, which is roughly the size of an AirPods case, way more solid. A small piece of self-adhesive foam has also been added to the internal plunger to dampen the loud mechanical "click" of the singular navigation button, which was a common complaint from users of the first model.

On the software side, version two introduces a new partitioning fix that unlocks 5.5 MB of storage for books. The system also includes automated text compression now. Thanks to that, the device can now hold between six and ten full-length books at once. Other new features include a folder-based library system, a storage indicator in the web interface, and the ability to jump to specific page positions, which was technically impossible in the single-button UI of the original.

The project is still available as an open-source build - the dev has listed two case designs and all the firmware versions for €4.90. Parts cost approximately $30. All said and done, Lagier's design definitely looks to be a fun and functional alternative to simply reading on a smartphone.