Oddly Specific Objects has launched a crowdfunding campaign for the Open Book Touch, an ESP32-S3-based e-reader with a 4.26-inch e-paper display with 480 x 800 resolution and a capacitive touch screen.
The open-source hardware device comes with 16 MB flash, 8MB PSRAM, a frontlight with warm and cool LEDs, a microSD card for storage, and an 800 mAh user-replaceable LiPo battery with everything housed in a 3D printed enclosure.
Open Book Touch specifications:
- SoC – Espressif Systems ESP32-S3 dual-core MCU with Wi-Fi and Bluetooth LE connectivity
- Memory – 8 MB octal SPI PSRAM
- Storage
- 16 MB quad SPI flash
- MicroSD card slot
- Display
- 4.26-inch, 480 × 800 e-paper; 1-bit and 2-bit grayscale with dithering
- Capacitive touchscreen based on FT6336 low-power controller
- Frontlight – five warm + five cool LEDs, independently dimmable
- USB – USB Type-C for power/charging and programming
- Misc – 3D-printed plastic enclosure; snap-fit, with 3D-printable CAD for custom shells; note: injection molding possible as a stretch goal
- Power Supply
- 5V via USB-C port
- 800 mAh user-replaceable LiPo with integrated charging and monitoring
- Dimensions – 78 × 120 × 10 mm
- Weight – 85 grams
While the Open Book Touch can be used as an e-paper dev board programmable with Arduino or CircuitPython, most of the firmware/software work has been done to create a nice e-book reader.
The default firmware has been written with the ESP-IDF framework to optimize performance and power consumption. It relies on Focus, a lightweight, platform-agnostic C++ UI framework for resource-constrained embedded systems, inspired by NeXTSTEP’s AppKit and Apple’s UIKit, which comes with view controllers, a touch-and-gesture system, a full set of on-screen widgets, and even an on-screen keyboard.
The firmware supports EPUB and plain text, with hyphenation, justification, and inline images, offers multilanguage support with around 70,000-glyph Unifont and a UI localized in seven languages, including right-to-left ones, fast refresh performance between page loads, and a DRM-free experience allowing you to transfer your books over WiFi through a built-in web interface.
Open Book Touch is open hardware with MIT-licensed firmware, schematics, board files, enclosure CAD, and source code to be released before shipping, although the source code for the Focus application framework has already been released.
There are plenty of e-book readers with touchscreen support, such as the Kindle or Kobo Clara BW, and some other readers do not require DRM, have a replaceable battery, and partial open-source support, but none of them have all these features in one device as the Open Book Touch offers. The main downsides I see are the smaller display and the limited number of supported book formats (for now). Another open-source hardware ESP32-S3 e-book reader not in the list above is the Diptyx E-Reader, which has a different dual-screen design and relies on physical buttons instead of a touchscreen for user interaction.
The Open Book Touch e-book reader is now available on Crowd Supply with a LiPo battery and a microSD card for $149. There’s also a $249 Open Book Touch “Author’s Edition” with a premium enclosure, but details are sparse for now. Shipping is free to the US and $12 to the rest of the world. You’ll need to be patient as rewards are only scheduled to ship by April 2027.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
Support CNX Software! Donate via cryptocurrencies, become a Patron on Patreon, or purchase goods on Amazon or Aliexpress. We also use affiliate links in articles to earn commissions if you make a purchase after clicking on those links.
