So, during the Half-Byte Console project, I purchased quite a few PS/2 style PC keyboards. Since the project is pretty much over, I have a few of these keyboards still. They are actually fairly decent keyboards for the price. Well, I had envisioned a future Half-Byte Computer living in something like a keyboard, like the old Commodore 64 or Vic 20. So, I set out to build one.
I wanted to use one of my Half-Byte Console boards, alas, though, it is too big. Since I ordered a truckload of Arduino Mini Pro’s, and they are really small, I used one of them.
I grabbed one of the keyboards and took it apart. It is really simple, a standard membrane matrix with full travel keys. However, even though it is a full size keyboard. there isn’t much room inside. However, there’s enough for the mini pro, wires and not much else. I had to cut holes for the power connector and video out.
What I was not going to do this iteration was include sound, nunchuck or FTDI connectors. That can all come later. I’m putting HB Tiny Basic on the this one, so I won’t need to be programming it often. The nunchuck will be easy enough to add later, as will sound. Just not that industrious at the moment.
I cut the cable from the keyboard as the pc board inside is marked and easily accessible. I wired it directly to the pro mini: data to pin 5 and clock to pin 4.
I decided to put the video jack on the left side, but first had to cut a hole for the connector. Next, I put the power jack on the bottom, where the keyboard’s cable came out. I had to enlarge that opening and super glue the connector. Next, I wired up the video out jack and the two resistors (470 ohm and 1kohm) to the pro mini (470 ohm to pin 9 and 1k to pin 7 see my previous postings on the video out subject.) Then the power was wired up and I tested the whole thing. Amazingly, it worked. It took two attempts at laying out the wire and board to get the case to go back together and for all of the keys to work.
NOTE: yes, the wiring is a bit sloppy, but I’m no Ben Heckendorn and this was for me. I will clean it up when I add the other connectors.