This project shows how to control big, scary 120V AC-powered devices using wireless serial communication and Arduinos. Specifically, I'll use a set of blenders as "musical" instruments controlled by a tilting iPhone.
Ever been scared to venture into the world of controlling AC power from your microcontroller? Me too. And that’s smart, because household AC can hurt/maim/kill if you’re not careful. The PowerSwitch Tail is a safe, easy-to-use AC relay that is triggered with a mild-mannered 5V DC signal from your Arduino or other microcontroller or circuit. Computers can talk to Arduinos directly, but adding XBee radios to the mix makes your serial communications wireless.