An Arduino can be used to test the life of any battery with less than 5 volts, Boxall says. So, for a quick way to see how much juice your AAA, AA, C, or D batteries have left, build this ...

This project is to prototype a set of self-powered (such as piezoelectric, thermostat, solar, etc) embedded sensor systems for pervasive computing. A tangible exam is a body-temperature powered motion ...