this will teach you some simple redstone wiring on the game Minecraft.
Step 1: Redstone Clock/Loop
this step shows how to make a redstone loop/clock
Step 2: A Piston Alternative to the Previous Step
this step shows you how to make another redstone clock/repeater but looks better and gives a quicker pulse of energy but is a little tricky.
Step 3: Piston Door
this step shows u........blah blah blah, READ THE TITLE
place everything like i have and it should work