Let's Make Robots!

What are Toilet paper Rolls For??!@?!??!?!?!?!?! Answer is here

What are they for? What are some good uses... List as many as you can....

 

Arduino Motor Driving Circuit.... What do you think?

I have one I/o pin going to a relay dpdt http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=843649 i then determines forwards or reverse. Then a second I/0 line to a NPN transitor to turn the motor of or on. This would have the capability of just forwards reverse and off. This is good because it takes on two i/o lines and is able to have just those parts because the coil would be able to run of the  40 mA the arduino pin can source

Help with Controller Mod. Help with circuit

I recently started to play a game on my xbox. It requires me to pull the left trigger very very fast. The trigger is ran off a potentiometer.  The controller "fires" at a certain point. I need to make a circuit that can do a pretend pull repeadatly. So it has to be an ajustable voltage that can repeadtly go when I press a button for a couple seconds. So it can be sometime of resonator or something. I am not sure how I could make something that fire the potentiometer to fake a couple "fires". I will get more information later when i open up the controller.