programmable power controller
The plugduino is not so much a groundbreaking concept as much as it is a solid project build and useful device to keep around. The plugduino is featured in a step-byp-step instructable to help you learn a bit about how to wire a 120V circuit safely and how to use an arduino to control everyday real work devices.
The arduino is a great introduction to programming and prototyping, but using it in a high voltage environment takes some work; the microcontroller only powers low ( ~40 mA ) devices. The plugduino uses a SeedStudio Relay Shield that attaches to the arduino to provide 4 high voltage contact relays to control 120V devices.
Four inputs (more if you like) can be connected to the plugdruino using the 10 bit analog inputs, which allow you to write programming code that can control the relays in smart ways. For example, you might wire up a temperature sensor to turn on a cooling fan, a motion sensor to turn on/off the lights, and so on. Image how this will rule your next haunted house.
To aid in programming ( and provide some eye candy ) there are 8 indicators; 4 show the inpout sensor voltages, 4 show the outlet states. This makes it easy to see your logic in operationand verify that the device is functioning properly.