Arcade Controller Project [Part 2]

After mapping the keyboard buttons, I pulled out the keyboard control circuit. I de-soldered and removed the connections for the flimsy circuits and then attached 2 bits of IDE ribbon cable that I pulled apart. The result is in the picture shown.

Notice that one ribbon cable is connected to an 18-pin connection, and the other is connected to an 8-pin. These exactly correspond to the 18x8 key map that I've made.

At this point, I tested the keyboard controller - no sense in going too much further if I've melted or otherwise damaged the controller, after all. The easy way to do this is to hook up the USB cable (I've detached it while doing the soldering) and plug it into a computer. Open up Notepad, and pick a letter key from the handy map you've made. I chose Y. Find the corresponding wires, strip a little of the rubber shield off the end, and touch them together. You should now have the letter you've chosen filling up line after line in Notepad. It still works!

**NOTE: It's much easier to use a laptop because you still have access to the built-in keyboard. However, I've seen Windows XP detect and utilize 2 USB keyboards simultaneously.**

At this point, I should explain where I'm going with this ribbon cable. I decided that trying to connect the better part of 100 wires (45-49 inputs x 2 wires each) to only 26 contact points would be less than ideal. So I've picked up some experimenter board (AKA 'matrix board' or 'perf board') from Jaycar. The particular type that I've purchased (see right) features pre-traced channels running the length of the board. This makes it ideal for my uses - remember, the 8 y-coordinate channels have 18 possible x-coordinate connections.

I've cut the board into 2 pieces - one is 18 channels wide with at least 8 holes per channel, and the other is 8 wide with 18 holes per channel.

I then soldered the 18-wire ribbon cable (x values) like so. Looking closely, you'll see that I now have plenty of solder points for wires from each controller. From here I'll attach the similar board for the y values.

At this point, it's getting to the time where I need to start actually building the case that's going to house all of this intricate mumbo-jumbo. The main problem I'm encountering is too many ideas for cool features. I've realized that I should have invested more time an effort into the planning phase, but meh.

Also, if you're interested in the overall cost, at this stage I've spent a whopping $6-$7 on the experimenter board. Everything else I had lying around or got for free. A 25W soldering iron is about $10 and solder is another $8 or so at Jaycar or Bunnings. An IDE ribbon cable to hack apart is something you can probably pick up free at a PC parts store - it's now obsolete technology. Otherwise, I've got about 30 spares :) .