Step 1: Materials
-1 9v Hobby Motor
-1 Plastic Wheel from Parallax item #721-00001
-1 HomeWork Board from Parallax item #555-28188
-1 Sound Impact Sensor from Parallax item #29132
-1 Solderless Breadboard from Parallax item #700-00078
-1 H-Bridge from Parallax item #603-00019
-2 Alligator Clips from Radioshack item #270-378
-Jumper wires from Parallax item #800-00016
-Spool of Wire from Home Depot (For wiring the sensor through the door frame and the wiring too long for the jumper wires.)
-Basic Stamp Editor v2.5.3
-2 L Brackets from any hardware store.
We also used various sizes of wood, but that is for our model door.
The motor listed above meant for our scaled down model door and will not likely work on the bigger or heavier doors, but may work on normal doors that are light weight. For the bigger and heavier doors you might want to use a motor with more power and maybe a bigger wheel.