Containerized Particulate

Generally when I’m involved in creative projects, I tend to try to keep things relatively simple, technically. This is partially a conscious decision, as I don’t want technical minutia getting in the way of creative expression, but it’s also a constraint of my so-so technical background. At any rate, I’ve been working on a few projects lately that involve pretty simple requirements, for which I’ve found relatively simple solutions. The first, I’ll write up today. I’ll save the other for soonish, once I’ve got it figured out 100%.

For the first project, the idea was to make a tactile interface out of conductive material, to provide data about who’s touching what, when, and to what degree. I settled on using an n in n out audio interface as a sensor array. The idea is to feed back each channel output back into its own input, turning the combined channel into  I/O in the sensor array. Each channel has a unique frequency assigned to it’s output, and a notch filter on its input making it ‘deaf’ to its own tone. When a user touches two or more of these I/O channels, their skin conducts the audio signals from channel to channel, and each channel registers the amplitude of the other tones it’s receiving. My setup right now involves insert snakes, with the mono ends plugged into the input / outputs of the audio interface, and the TRS end plugged into a 1/4″ stereo jack with the signal lines tied together.

Currently, the Max patch tells you the sum total of one channels tone being picked up on all others. Later, I may spend some time turning it into an n by n matrix, providing more specific information on channel to channel relationships. I don’t really feel a need for all that extra data right now, though.

Also, I don’t know why it would, but this patch (and misuse of your audio interface in this way) may totally destroy your interface / computer / life. So don’t say I didn’t warn you. Here’s the patch – sensor.maxpat (right click ->save as…)