10 key board. top left switches mode (ascii binary, hex, braile etc indicated using a rgb led under) bottom centre key is for 00000000. press any combination of keys and upon release correct output is created. eg, in Hex mode, if the last 2 keys were pressed output would be 2, if all 4 right keys were pressed output would be F. Uses an arduino and the schematics from http://www.practicalarduino.com/projects/virtual-usb-keyboard for USB output. Code to follow some day.
Finally uploaded the code for the serial mode, and all you need to do is connect 9 push buttons to pins 2 to 10 and gnd.
Functioning in this version are "a" to "z" lower case, the enter key and the space key.
As there is no delete in serial, this is not activated, and i have left placeholders for other possible braille inputs. i haven't included numbers as these are the same as "a" to "j" in braille with a modifier character (much like we may use the # symbol)
I found a mechanical keyboard with Futaba clicky switches at a car boot sale. Just putting together my improved prototype, as well as using a teensy lc (thankyou HAD) to emulate a keyboard. The arduinos I have kept sending extra keystrokes over serial. Doing lots of SOLDERING right now.
After what seemed like an eternity, my microswitches finally arrived from China. Codeing has been a little irritating and I am leaving it serial only for the moment as that will work better for the #Braille Computer I am working on for the hackaday prize.
I have manufactured PCBs for a very similar device:
It has 3 boards: "Left Hand", "Right Hand" and "Thumbs" and uses Arduino Pro Micro.
To make a Braille keyboard, simply solder 8 switches to the "Hand boards", the "Thumbs" is not necessary (just put a separate switch with wires).
Let me know if you are interested.