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VSA Keyboard Hack
This tutorial will show how to hack a standard PC keyboard, to trigger a VSA routine via a pressure mat.
VSA uses the following keyboard inputs when a routine is loaded:
| Play all | ENTER |
| Loop play | @ |
| Play to first marker | ] |
| Play from second marker | [ |
| Play between markers | TAB |
| Play frame at first marker | CTRL+TAB |
| Reset Device positions | Backspace |
Also, VSA routines can be started from a command line:
"C:\install_dir\vsa.exe" "yourvsaroutine.vsa" /play /minimize /close
| /minimize | Before loading the routine, VSA is minimized and appears only in the task bar. VSA is not made the active window. |
| /play | After loading the routine, VSA will begin execution. |
| /close | After the first execution of the routine, VSA will automatically shutdown. |
Note: All keyboards are not the same so your mileage may vary, but the concept is the same.
1) Disassemble the keyboard. Usually there are 8 to 10 screws in the back holding the shell together. Split the shell into two and you should see something similar to the below picture. Flip the rubber membrane over enough to see the ENTER key pad.
2) Remove the small circuit board. You now need to trace back to the contacts in the top of the below picture. This keyboard has two Mylar circuit boards with a clear Mylar insulator in between. Pressing the top Mylar circuit board completes the circuit with the bottom Mylar circuit board. So when you press the ENTER key the two lines complete the circuit.
3) Start with the top Mylar circuit and trace it all the way back to the fingers in the above picture. Do the same for the bottom Mylar circuit board.
4) I marked both fingers with a Sharpie. You can't see the mark below in the second picture but it's the second finger from the right.
5) You now need to find those two point on the BOTTOM of the circuit board. The easiest way I've found is to draw two marks on the circuit board edge that MATCH the two fingers you marked previously and follow those marks to the underside.
6) Using an exacto knife, I gently scrap away the top coating of varnish on the two traces I marked, until I see copper.
7) I solder a wire to each trace.
8) I solder the other ends to a 1/8" MONO jack
9) I drilled a hole in the back of the keyboard.
10) Finished. I solder a 1/8" MONO plug to the pressure mat wires and when I'm ready to go live, I plug the mat into the keyboard. Stepping on the mat is equivalent to pressing the ENTER key on the keyboard.
