The Cup-O-mo-phone is essentially 4 touch sliders made out of video cassette tape. The video cassette tape combined with some elastic band turns into a cheap touch slider. The elastic bands keep the top tape separated from the bottom tape but not far enough that pressure won't join the tapes.
I use the arduino's A/D to read in the variable voltage from each of the 4 touch sliders. Then I use csound to convert it into a musical instrument.
For the source code to the perl script, csound instrument and samples, and the arduino source code see: http://churchturing.org/x/SuperCup
The circuit is a voltage divider, I'm using 47k resistors and start off with a 10 ohm resistor at the start. Because I didn't double up the paths the multitouch aspect doesn't work yet and would require more wiring. I want to jam that little breadboard in the cup so wiring will be less of a hassle. http://en.wikipedia.org/wiki/Voltage_divider
- For more information of using video cassette tape for a variable resistor see: http://itp.nyu.edu/physcomp/sensors/Reports/HomeMade
- Note: I found that newer cassettes did not work, their tape did not conduct.
- Older tapes did seem to conduct, so test your tapes before you destroy them (just use a multimeter and flip the tape open and test).
I have a bunch of a mercury rocker switches I want to add to it.