USB Keyboard Foot Pedal Button

A friend of mine was saying that he would love a foot pedal to use while playing W.O.W. to control his chat application (Vent).  I told him that would be super easy and whipped this out the next day for him.   Here is how I ended up doing it...

Parts List:
- USB keyboard
- Dremmel with plastic cutting disk
- Project enclosure (optional; you could probably figure out a way to use the case from the keyboard of you think long enough about it)
- Multimeter (optional but sure helps a lot and makes things go faster when decoding the key matrix)
- Drill for drilling hole in project enclosure
- Momentary push button switch
- Some hook up wire
- Soldering and some solder
- Xacto knife
- Screw driver
- Hot glue gun

Start by taking all the screws out of the bottom of the keyboard and put them aside encase you need to use any of them again later. Figure out what key you are trying to find, if you have a multimeter it's time to bust it out. Set it to the continuity tester function. Hold one probe on the location of the key you are looking for and then start poking at the pins across the top that would connect to the pcb. Even though continuity normally beeps but watch the output since most of the runs are too long but the reading willl change, it's just not high enough for the beepy beep. Now do it again foe the second layer cor the same button pad. When you are done you' should have found 2 pins on the pcb. All the ksyboards that I have ever used have a weird black coating over the pads on the pcb which must be conductive but it doesn't lend itself to soldering to it, so I just use a xacto knife and scrape that black stuff off. When you are done you should have some shinny pads you can solder your hook up wire to for you button. Now that you have that black stuff scrapped off time to make sure you have the right ones. Plug the keyboard into a computer, open notepad or any other text editor applicaion, and take a wire and bridge the 2 pads. Your desired character should appear, if it doesn't then double check all your traces. Disconnect the keyboard from the computer and solder your leads from your button on to these pads. Reconnect and make sure you still get the desired character, and if you do box that bad boy up and you're ready to go.