Hacking a Keyboard Matrix

**phokur** · 01-19-2009, 04:08 PM

Hi! I need a 8 key input device with the enter key in a row, like the numbers above the letters on a keyboard.
Like this:

I broke apart an old ps/2 keyboard hoping I could pick and choose and rearrange the keys, but the matrix looks intertwined and I'm sure snipping any of the matrix will bust it.

My project isn't for a car, but this kind of knowledge would only be found in improv hackers like you guys. I'm building a internet radio streamer inside an antique radio. I made a batch file to load winamp stations when a key then enter key is selected. Just need to make the input device. The number keys (1-9) are the perfect spacing to fit into the radio. So I'd like to use those 1-8 and then replace 9 with the enter key.

Any suggestions? Thanks in advance.

**phokur** · 01-25-2009, 01:30 AM

As an update, my program no longer needs the enter key. So I just need the numbers 1-9, any way to successfully seperate them? Here is the keyboad matrix:

**zeecue** · 02-08-2009, 10:48 AM

Just follow the lines that go to from the buttons to the pins on the controllor board, really simple, just take a pen and make a line all the way so you can see it easier.

**Bugbyte** · 02-08-2009, 11:19 AM

Alternatively, you can use an IPAC keyboard emulator. They go for about $40 bucks. You just connect the buttons to the terminals on the board and you can program the IPAC to generate any key or combination you want.

**phokur** · 02-08-2009, 07:39 PM

I didn't understand how they work, apparently when a upper matrix dot contacts a lower matrix dot the controller sees two unique lines crossed and generates a letter. So if you figure out which two lines need to cross to generate a '1' you can make a switch manually cross those lines. I'll post the finished product when I find some contact switches. Thanks for the replies!

**Dingo509** · 02-09-2009, 02:38 AM

Why not just try a small USB number pad? like this...

Seems to me hacking this would be easier than a full keyboard. And i have seen them at places like walmart for under 10 bucks.

Dingo

**phokur** · 02-09-2009, 08:25 AM

It's true, but I had a spare keyboard laying around. Plus I'd prefer to use PS/2 and I think those number pads usually use USB. Thanks for the suggestion though.