As somewhat of an iteration of the 555 servo, I decided to make loud noises.
By adding an adjustable sound impact sensor and another 555 timer in bistable mode, I was able to make the fancy cardboard arm of the servo move clockwise when the sensor heard a loud noise and move counterclockwise when I pressed the reset button.
That's really all there is to it. =) I've never worked with a microphone in an analog circuit, so this was very new -- and fortunately quite easy. It turns out that dividing your circuit into independent manageable chunks (like code!) is a Good Thing.
