Step 8: Variations and Notes


  • Build massive sensors
  • Optimize the resistors and code for things that vibrate quickly, and use it as a pickup/microphone
  • There are probably other tricks for decoupling the system from AC hum (a huge capacitor beteween the plates and the ground?)
  • I've experimented with shielding the plates on the bottom, but it only seems to cause problems
  • Make an RGB or HSB color picker
  • Control video or music parameters; sequence a beat or melody
  • Large, slightly bent surface with multiple plates + a projector = "Minority Report" interface


The Arduino playground has two articles on capacitive touch sensing (CapSense and CapacitiveSensor). In the end, I went with an inversion of a design I stumbled across in a friend's copy of "Physical Computing" (Sullivan/Igoe) describing how to use RCtime (the circuit had the capacitor and one resistor fixed, and measured the valueof a potentiometer).

The microsecond timing was accomplished using some slightly optimized code from the Arduino forums.

Again: just from starting at tons of theremin schematics I don't completely understand, I'm well aware there are better ways to do capacitive distance sensing, but I wanted to make something as simple as possible that's still functional. If you have an equally simple and functional design, post it in the comments!

Thanks to Dane Kouttron for tolerating all my basic electronics questions and helping me understand how a simple heterodyne theremin circuit works (originally, I was going to use these -- and, if tuned correctly, it would probably be more accurate).

I cant seem to get it to work :(

The sketch runs and in Processor i can see that it says "defining boundaries" whenever I left mouse click

But nothing after that!


(I am using Make:'s code btw)

Is it possible to use this to search the internet?
Spydamonky4 years ago
Im going to try combine this and a 3x3x3 bicolor led cube to make a interactive 3d tic tac toe! im so excited!
olavxxx5 years ago
I have thought about a good usage for this.. When some exhibit (museum or whatever) has some audio/video show.. then you want to let users change video or restart it or whatever.. regular keyboards and such gets easily worn out, but how can you wear out air?? lol.. would be a super usage for this.
olavxxx5 years ago
hahah, this instructables site is EPIC.. so much fun stuff here :-)
kylemcdonald (author)  olavxxx5 years ago
Glad you enjoy it, check out my website for more stuff!
eolverag6 years ago
nice work
kylemcdonald (author)  eolverag6 years ago
Thanks. I'm working on a new version right now that stays as simple as possible but has faster a sample rate and lower noise.