HWP #001 - The USB NES Controller
Background story
I've always thought that the NES is simply the best console ever made. I still remember how extatic I was when I got it for my 6th birthday, but alas - good things don't last forever. It broke, naturally, and the only thing I had left was the controllers. Now I'm very glad that I did not in fact throw them away.
One dark saturday night, I suddenly had the extreme urge to play some good old-fashioned Nintendo games. The only correct way of doing this would be on the dedicated console, and preferrably on a 26" CRT television set (ahh, the memories). I decided to go for the second best option - attempt to hook it up to the computer, and make the computer use my dad's telly as monitor. A brilliant idea to my ears, so I just got started.
Planning
Obviously, the first thing I would need was some USB HID device to manipulate. It is of course possible to make one from scratch, but i simply didn't have the necessary equipment for that at the time. After going through some boxes of old junk, I found something that registered as "HID Device" when connected to a computer. Perfect.
Next step was to study how it read keys. It turned out that it had 16 keys in total, and those were based on two common grounds. This means that I had to do a small modification of the NES controller's PCB - I had to cut the ground trace in two right after the directional keys. From there, I simply had to figure out which traces went where - see image below - and solder on cables to the correct points on the HID PCB.
My shoddy attempt at hand-drawing. Don't ask.
I decided to do the rest of the planning on-the-fly, as it seemed like it would be a rather simple task overall.
Compiling
~documentation to be concluded~