Hey cool, sticky status
Actually I've been considering ways to make a mod like this more accessible to people (should they want to try something similar) and I think there are some options.
When I did the mod I used the stuff lying around, but there ARE better parts out there. In particular this part is VERY interesting: FT245R
. FTDI makes some great USB converter parts. What makes that one interesting is that it has what's called a "bit banging" mode, whereby you block send data via USB and it sends it out 8-bits at a time FIFO style. Key thing is it requires NO firmware code (no having to learn assembly language), and they even supply a royalty-free DLL driver to link into the host side program (no having to write a driver). Very cool stuff (and for anyone looking, Mouser carries the FTDI line, www.mouser.com
- search for ftdi)
But, it has a drawback, the microcontroller I used runs an internal routine to generate PWM signals to control brightness. That part would lack that ability, so it could only turn LEDs on or off (that's assuming the part is coupled into a 74595 shift-register chain like the one I used). On the plus side, hardware for that would be quite simple, and the behavior would be controlled entirely by the host-side program.
Going with a full microcontroller, there is an option that looked good. Atmel makes an AVR part that can do USB, but even better they make a complete eval board for it that's completely ready to go: AT90USBKEY
(mouser carries that also) That eval board could easily fit into a Deck keyboard. What's great about that is that it has 48 general-purpose I/Os built-in. Not enough to cover a 106 LED board, but shift registers could be added to it. I think those guys also supply USB code. Going with that would require learning how to code a microcontroller (really not that hard).
If I were to start from scratch I would go one of those routes.
One other place I should mention, SparkFun
. I discovered that place months ago, and they supply all kinds of good bits that could be incorporated into a mod. They have graphic LCDs, multicolor LEDs, and as I just learned today they do PCB services (they consolidate many PCB orders into a bulk buy, so they have exceptionally low prices and can do very small orders, even single boards).
Hopefully some of this will help jump start a mod if someone is thinking about it.