Video: There are all sorts of variations on Raspberry Pi-powered home automation systems, but ARM Tutorials shows off a pretty simple project that uses Twitter as the backbone. The Pi is hard wired into a home automation board that controls a fan, light, AC and the temperature. It's then controlled over Twitter direct messages so it's super easy to check the status or flip the toggle on any of the connected devices. The Twitter link is a pretty handy way to get around some of the programming requirements that would otherwise be required here, so it's worth taking a look at how it's done here if you're making your own home automation controller. Head over to ARM Tutorials for the guide.
Pi Buddy - Twitter based automation [ARM Tutorials]