Prototype 6 with Potentiometer and Sound Output

We made two big improvements to the prototype...

1. We added a potentiometer as a variable resistor. This allows us to 'tune' the range of input values.

You can see in the video that we want to set the resistance so that when no one (or hand) is around, the circuit is completely off, and when we put our hand close but not touching it is fully on. This potentiometer is rated 10 kOhms, with a variation +/- 20%.

2. Sound as output. The first component we tried was a simple buzzer.

We're using a simple on/off pin of the Arduino, so at this point much of our previous work with getting a range of inputs is now moot. In this version of the prototype, we just chose a threshold to turn the buzzer on.

3. More fun sound!

We picked up this little recording module for about $10 at RadioShack. It is a self-contained unit with enough memory to record up to 20s of sound, a thin little speaker, a 'record' button (it uses the speaker as a microphone too) and a 'play' button, all powered by a 9V battery. Of course our hope is to hack the trigger switch so that we can us it as output for our Arduino. Stay tuned!