I bought a liquid level sensor from Sparkfun to control the audio playback. After playing around with it a bit I’ve figured out how to use the sensor. Functioning as a voltage divider, all you need are connections to the two middle pins of the sensor, and wire it up like an FSR or any other voltage divider. Here’s a video of my testing it out with my patch:
Liquid Level Sensor Test from Matthew Leon on Vimeo.
The sensor:
