Anna-Lena Marx's ZEReader Is an Open-Hardware, Open Book-Inspired, Raspberry Pi Pico 2 E-Reader

Embedded systems engineer Anna-Lena Marx has released ZEReader, an open-hardware electronic book reader originally developed as the final project in a bachelor's degree in electrical engineering — taken on "as a hobby besides work."

"ZEReader is an open source hardware and software e-reader platform," Marx explains of the project. "Originally developed as my bachelor's thesis in electrical engineering, it has since evolved into a dedicated hobby project. Most e-readers today are based on Linux or Android, which is often overkill for a device designed simply for reading. Inspired by the Open Book Project, this led to a key question: could a simple, microcontroller-based e-reader get the job done just as well?"

The ZEReader itself is a custom PCB designed to house a Raspberry Pi Pico 2 development board and its RP2350 microcontroller. The board also includes a lithium-polymer charge controller, a USB Type-C connector for charging — but not, in the current revision, data transfer — a microSD Card slot for storage, and a driving circuit for the electrophoretic ePaper display which dominates the device's front.

The software, meanwhile, is built atop the Zephyr real-time operating system (RTOS). "As a student with a primary focus on the hardware development during my thesis," Marx explains, "I needed a robust software framework that offered a high level of abstraction and a large ecosystem of pre-built drivers. Zephyr provided exactly that, allowing me to bypass the tedious work of writing every driver from scratch."

The firmware is a work-in-progress, Marx admits, but already ticks the major boxes required of an electronic book reader: it can handle uncompressed EPUB files, provides page-by-page navigation, can parse and render "basic formatting elements" from HTML markup, saves book progress, and allows the user to switch between different books stored on the microSD Card.

As Marx says, the project was inspired by Joey Castillo's The Open Book Project, which began life as a FeatherWing carrier to transform compatible Feather-format microcontroller development boards into fully-functional e-reader gadgets. The full-size variant was quickly followed by the Tiny Book, a standalone variant with integrated Microchip SAM D51 microcontroller.

Marx has released the project's source code and hardware design files in two separate GitHub repositories, under the Mozilla Public License Version 2.0 and the strongly reciprocal version of the CERN Open Hardware License Version 2 respectively — but warns that "while the first PCB is a functional and usable prototype, like any initial version, it has several design flaws that need to be addressed and also led to many new ideas that will be implemented in future revisions."

Additional information is available on Marx's website.