OPen Book: a fully open source e-book that supports all languages ​​and breaks down working principles (schematics, PCB, source code, etc.)

Open Book is an open hardware device for reading books in all languages ​​of the world. It includes a large screen and navigation buttons, as well as audio options for accessibility and ports to expand its functionality. Its fine screen printing aims to demystify Open Book's own design, breaking down for curious readers how the book works and how they can create one for themselves. Key Features: - 4.2" e-paper display driven via dedicated SPI bus. - Seven buttons (directional pad, select button, and page turn button) accessible via shift register, eighth button (locked) connected to SAMD51 Interrupt pin on main SPI bus with SD card detection. - LED for charging and full status, and red LED for general flashing. - 2MB for CircuitPython support. Flash Chip and Neopixel. - Second 2MB flash chip for universal language support with Babel - Access to two digital or analog pins via STEMMA compatible port with current and voltage protection. I2C interface. - Voltage monitors on the battery and USB power ports. - Audio combo jack with stereo audio output and raw microphone input. - A MAX4468 ​​microphone amplifier for amplified microphone input.