That's right, it's alive!
The Frankenkindle is alive, and fully functional. The 5-way keypad (up, down, left, right and center) and 'Home' have all been implemented with a substitute keyboard. (Also,if you turn up your speakers you may hear Queen playing Bohemian Rhapsody in the background - don't say I never give you anything.)
Functionally it's complete, but there's still a fair bit to be done to make it more robust. The Kindle itself needs to be semi-permanently mounted to the front panel rather than just resting on two wood screws. The circular interface board along with the flat cable connecting it to the Kindle are both quite fragile and will need to be covered. Finally, the cables will need to be routed in a more organized fashion.
Here are some pictures to better illustrate what you saw in the video. Keep in mind that this is a prototype if ever there was one. It's not pretty, but it doesn't have to be. It's functional. Once my sister has a chance to play with it I'll be able to take some good notes on what works and what doesn't, and fold them into the next revision. Right now I'm designing for what I think she'll need. The only way to find out if it's useful to her is to actually turn her loose on it and watch what happens.
The disassembled Frankenkindle. Front panel, Kindle, and control board are all visible.
Side view, showing the circular board used to interface the main control board
to the Kindle's keyboard input.
Rear view, showing the control board.
Power is supplied from a 5V "wall wart" style power supply and the 9-pin serial cable is used to provide an easy quick-disconnect for the new front panel buttons.
Closeup of the main control board.
5V DC power is fed through the black cable and used to power the Teensy controller directly (the long green board with USB connector). It is then fed through a series of diodes to provide a sexy red power LED and stable 3.3V for the multiplexers (actually closer to 3.5V, but who's counting?). The multiplexers are the surface-mount chips on the red breakout boards. The bank of resistors in the upper right form a series of voltage dividers, useful for dropping the 5V control signals from the Teensy into 3.3V signals suitable for use with the multiplexers.
And there you have it! More pictures will be posted to document progress on the enclosure itself. Also, be on the lookout for a full bill of materials (BOM) and more formal documentation.
Thanks for reading!