I'm trying to understand how an electronic musical instrument (called an e-chanter) works (imagine a recorder or other wind instrument, but with the holes replaced with metal contacts, and the sound played electronically, so no air is needed).
Basically, there are several metal contacts, as shown in this link: http://www.echanter.com/home/howto-build#TOC-WIRES-SCREW-SENSORS
They each appear to be wired only directly to one pin of the arduino:
I can't figure out for the life of me how this works. Can anyone explain it, are the fingers being used as some kind of ground or what on earth is going on. I have a physics background so can understand some technical info, but just can't fathom how on earth this magic works.
Thank you very much