Which kit / board should I use ???   (( HELP ))

Currently I am researching ways to build a sound activated system.

Type of experiment: Build a board that controls a paintball loader.

Criteria to be met:

  1. It has to detect sound and activate a 9 volt powered hobby motor that could be found at any radio shack.

  2. Once it has been triggered by sound, the motor will remain active for a solid 1 second interval then stop running.

  3. If the sound is consistent, the motor will continually run until said sound has ceased.

  4. Must be able to use two 9 volts.

  5. Needs to be fairly small.

There are boards on the market sold just for this in the world of paintball, however, I am interested in building my own for use in side projects.
Also the cost of those boards are around 60 bucks, so that's another reason I want to make this work ( hopefully cheaper).

If anyone can think of the simplest and cheapest way to put something together, I would greatly appreciate the input.

--- Many thanks,

Heck, you could probably easily do this with a 556, a 2n2222 and a handful of passives (cost - under $5.00)...

;D

/remember - not every problem requires an entire microcontroller to solve...