Quantity   Component name
1 × Adafruit Powerboost 1000C For mobile usage, the Powerboost 1000C from Adafruit in combination with a decent rechargeable battery will provide not only power but also the ability to reload the battery using a mini USB connector.
1 × Adafruit rechargeable LiPo battery (compatible with Powerboost board) A LiPo or LiIon battery for providing power on the go. Best purchased from Adafruit for full compatibility with the Powerboost board.
1 × Adafruit NeoPixel ring with RGBW LEDs (alternative: four or mode single white LEDs) The smaller NeoPixel rings from Adafruit with the new RGBW LEDs add a nice ring light around the camera lens. Alternatively, you can just use a bunch of white LEDs in order to add some light for taking pictures.
1 × Adafruit mini metal speaker When not using headphones, a mini loudspeaker can be used for sound output.
1 × Optional: Adafruit SD card breakout board This one is optional: with an additional SD card breakout board, scanned images and texts can be stored separately from the operating system, allowing easier file transfer to an external computer.
3 × Pushbuttons One pushbutton is needed for triggering the scan procedure, two additional ones can be added for volume control. Additional buttons or a rotary encoder may be used for switching between different operation modes in later expansions.
1 × 1N4001 rectifier diode (for using NeoPixel elements) A simple rectifier diode for use with the NeoPixel strip or ring.
1 × Raspberry Pi The current prototype uses a Pi model 2. The plan for the intended first non-prototype version is to use a Pi Zero. It should also work with other Pi models, but you may need to adapt the case design.
1 × Raspberry Pi Camera module (alternative: USB webcam) Thanks to the new version of the Pi Zero, a Pi camera module can be used for taking pictures. Alternatively, you can use a USB webcam (which you can dismantle a little in order to make it smaller).
1 × Raspberry Pi Zero camera connection cable This is only needed if you use the new Pi Zero and Pi camera module for the build. For other Pi models, you can use the cables which are included with the Pi camera module.
1 × SD card One 8GB SD card (in micro SD format) is needed for the operating system and applications. A second SD card can be used in combination with an additional SD card reader in order to be able to more easily transfer the image and text files to another computer.
1 × USB to TTL serial cable (alternative: network adapter and cable or WiFi adapter) This is mostly needed for connecting to the Pi during prototyping and further development, and for installing software. Once the build is finished, it's only needed for updates - unless you add a WiFi adapter and connect to the Pi wirelessly..
1 × Optional: USB Wireless "nano" adapter (alternative: USB ethernet adapter and cable) In order to update the system components and install additional software, I am temporarily using an Edimax EW-7811Un WiFi USB adapter.
1 × Adafruit I2S 3W Class D Amplifier Breakout - MAX98357A (alternative: Pimoroni phatDAC) This small audio board can add sound output to the Pi Zero. On the other Pi models, it offers an easier way to connect a small speaker to the Pi without resorting to USB speaker boxes. The Pimoroni pHat DAC board can be used as an alternative.