Controlling AC power with a computer can initially seem to be a complex task, however with some thought and a few hours it's possible to control one or more relays with an Arduino-compatible board via almost any device with a USB output that can send serial text.
This has been demonstratred by Maurice Castro, who has connected two AC relay modules to his Freetronics LeoStick - which in turn is connected to a PC for power and control. The sketch (code) loaded into the LeoStick receives simple commands via USB and acts upon them to control the relays, all of which are sealed in a container out of harms way. Any programmer can then have their software send serial text out via USB and control the relays without too much effort at all.
Need a small Arduino-compatible for use with your own control projects? Then check out out our LeoStick. It's the Arduino Leonardo-compatible board that's cheaper and smaller than the original:
Apart from being one of the smallest Arduino-compatibles on the market with USB, it also has an onboard RGB LED and piezo which can be used a knock sensor and various tune and sound effects. Plus you can add extra circuitry with the matching protostick! For more information and to order, click here.