[Andrea] just sent us this great student hack he made for his room. He’s constructed an Arduino keypad door lock — without using any proper fastening hardware! The entire build is made … ...

[Runtimemicro] has the answer, at least if you are writing PWM code for the Arduino. Their free application lets you set a few parameters, visually see the results, and then generates code for you.

The Code Kit is an Arduino system in a box. It comes with a small rechargeable battery that can power an Arduino-based CodeBit with three inputs and three outputs.