Open Book is an open hardware device for reading books in all the languages in the world. It includes large screens and buttons for navigation, and audio options for assisting features and ports for extending their functions. This article is an e-book like this book for curious readers and how to DIY is like a book below.
The core of the Open book is the SAMD51J19A microcontroller, based on the powerful ARM Cortex M4, with 512 KB flash memory and 192 KB of RAM. It has 51 GPIO pins, while Open Book uses all of these pins as peripherals and extensions:
400x300 black and white electronic paper screen enables the core experience of reading. Be
MicroSD slots provide a large number of external storage for files.
The user inputs seven buttons from the shift register and the eighth button binds directly to one of the interrupt pins of the SAMD51.
The dedicated language flash chip stores the glyphs of each language and the space of Unicode data.
3.5 mm audio jack:
Dual DAC allows stereo audio output, SAMD51 function is enough to instantly decode MP3 file
The original input of the built-in microphone button of the headset can let the book detect up to four built-in buttons, depending on the design of headphones ...
The enlarged microphone input from the online microphone can be used with Tensorflow Lite to identify voice commands! In addition, just like recording. .
QSPI Flash Chip and State Neopixel support CircuitPython use case.
The STEMMA port allows you to add I2C sensors and external analog or digital inputs.
Of course, portable e-books, which means that its battery is charged with built-in LIPO, and you can even provide power from all functions from the sensor to GPS to WiFi to Lora.
The development board also added the above-mentioned microphone closing pin, and the green LED indicates that it is charged and provides a voltage monitor on VBUS to determine if the device is inserted. I have an Arduino development board support here, and I am studying a few libraries that support the book: a library called Open Book, used for external device interface; a library named Babel, located in language chip and adafrouit_GFX Subclasses are used for multi-language typography. Be
I have expanded my own custom electronic ink driver, which contains waveforms for quick refresh, grayscale mode, and partially refresh. There is also a place that needs to be improved, my current waveform will lead to temporary ghosts after a while, I am worried that it may have a negative long-term impact. But I feel that if I add an inverse phase on BB and WW, it will improve the situation (at a price of a little bit).
In addition, I also trained a Tensorflow Lite model to identify the voice command on the built-in microphone to showcase the current idea of future accessibility work.
As of now, this e-book project is OK. However, there are still two challenges:
When inserting a USB power supply, I noticed a little noise on the microphone input, I think this is related to the way I connecting the USB shield line to the ground layer. When modified, I will add an RC filter between the USB shield and the ground plane.
The right point button on the previous page is excess, and it is difficult to press them in the case of loading the outer casing.
Several "Lock" buttons on the development board have been lost for a while, which tells me that there is a mechanical failure there. Now, I just add a bunch of solder to keep the right angle button security, but I need to find some buttons with nails to reduce the pressure of repeated press, or design other support methods.
I am evaluating some very small white right LEDs to expect the headlights that may be realized, although there are some challenges there. The above is the full content of my project, I hope everyone likes it.
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Article Source HackADAY
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