Joey Castillo Unveils the Tiny Book, a Shrunken Yet Powerful Alternative to the Open Book E-Reader

Joey Castillo's Open Book project has a new member in the form of the Tiny Book — a cost-reduced, ultra-compact version of the open hardware e-book reader that could easily pull double-duty as an ePaper badge.

Castillo unveiled the Open Book last year, as a response to the often locked-down and heavily proprietary commercial ebook readers available on the market. The Open Book is an ecosystem of devices, initially starting with an E-Book FeatherWing add-on for Adafrut's Feather-compatible boards plus all the supporting software required to fulfill both the project's primary goal of reading electronic books and as much additional functionality as can be feasibly crammed in.

Now, the family has a new member: the Tiny Book, a standalone version of the Open Book that aims to bring as much of the functionality of its bigger brother across while reducing both the size and the cost.

The Tiny Book is based on a Microchip SAM D51 microcontroller in a QFN48 package — reducing Castillo admits, the hand-solderability of the project — and a 2.7" ePaper screen, moved to the main SPI bus from the dedicated SERCOM of the larger 4.2" version. The seven front-facing buttons are gone, replaced with five capacitive touch-pads — which Castillo is hoping will include swiping gestures to replace the missing page-turn buttons.

Other changes to the design include making the on-board user-programmable RGB LED right-angle edge-mounted — "which honestly the Open Book should have done to begin with," says Castillo — and switching the headphone jack from stereo to mono, though retaining the microphone input.

The biggest shift, however, is the loss of Feather compatibility. "This is a big loss," Castillo admits, "no way around it." The Tiny Book also drops to two STEMMA ports, loses the dedicated Babel chip for multi-language font support — to be implemented in software loading glyphs from the microSD, most likely — and removes the lock button in favour of an automated sleep timer.

Images of the first assembled Tiny Book are available on Castillo's Twitter, while the schematics and board layout files can be found on the Open Book GitHub repository.