Canute’s Estimated Specifications
The Canute uses radically different internal mechanisms from the prohibitively expensive existing Braille displays, which allows it to have the unique format of 40 characters per line over as many lines as is needed.
It uses far more affordable actuators, and because it runs off Open Sourced ebook software that can be freely changed users can add their own functionality or adapt the user interface to their tastes.
Specification is subject to change as the design continues to evolve. This specification refers to the final design which we aim to take to market, rather than the latest design (the Mk10 prototype).
(N.B. 1mm = approximately 1/25“.)
- 1.2mm dot diameter.
- Adjustable 0–1mm dot protrusion from reading surface.
- Dot profile a perfect dome.
- 2.5mm dot-to-dot within cells.
- 4mm cell-to-cell, from centre of dot one to centre of dot one.
- 15mm line-to-line, from centre of dot one to centre of dot one.
- Dots are hard plastic, like signage Braille, and therefore cannot be compressed like ordinary refreshable Braille.
- 40 cells per lines, 9 lines = 360 cells of Braille. This makes the reading area compatible with preformatted BRF and PEF pages with the standard 25–27 lines, which it splits into three sub pages.
- Reading surface a single plastic sheet with a paper-like feeling.
- Reading surface is a slot-board, rather than a pin-board as used in refreshable Braille displays, meaning two small 2mm by 8mm slots for every cell, as opposed to six 2mm dia holes for every cell.
Input and ports
- Nine buttons along the left-hand side of the Braille lines, acting as selection buttons which correspond with menu items on each line.
- Three large buttons — Previous, Home and Next — below the ninth line.
- On the left-hand side of the back of the unit:
- One USB-A port for loading books via a USB memory stick.
- One USB-B port for connecting to an external computer to act as a display.
- One small binary switch for switching between stand-alone mode (potentially making use of the USB-A port) and display mode (necessarily making use of the USB-B port).
- The power-in port, accepting standardised laptop power supplies at 19V, on the right-hand side of the back of the unit. Base unit will be mains only in its initial iteration.
- Approximately 35cm left to right, 35cm front to back, 6cm top to bottom (14” by 14” by 2.5”).
- Approximately 3.5kg weight, including power supply (8lb).
- One piece case front to back, including reading surface, of white or metallic plastic. Supported at the sides by oiled hardwood extending front to back.
- MDF base plate and service hatch with six rubber feet.
- Bristol Braille logo (stylised ‘BB’) and Canute trademark engraved into the hardwood sides.
Firmware and software
- Open Sourced API to access Arduino compatible control board via USB-B port or custom stand-alone software.
- Includes Raspberry Pi micro-computer running stand-alone software from a Linux operating system (Raspian or RaspberryVI).
- Open Sourced stand-alone ebook reading software, written in Python, which provides compatibility with any BRF and PEF formatted files with 40 or less cells per line, and has basic ebook functionality comparable to an entry level Kindle.
- Can be reprogrammed (by logging into the Raspberry Pi) by users to change or expand functionality, using any Linux compatible language (Python, C, C++ &c.)
- Updates (‘reflashing’) are instigated by loading a zip file via the USB-A port.
- External Calibre ebook library plug-in to aid conversion from all common document formats (Word, TXT, PDF, Epub, Kindle &c.) to Canute compatible PEF format.