It’s every nerd’s fantasy — a “smart house” that knows when you left the lights on and turns them off, adjusts the heat and A/C according to the outside temperature, closes the blinds in the afternoon sun and reminds you to get milk at the store.

It may sound like something out of a 1980s sci-fi movie, but it’s not as far-fetched as you think. In fact, home automation is a burgeoning market with all sorts of toys available.

For most part, it’s a playground limited to a few lucky dot-com millionaires. If you happen to have sold YouTube for a billion dollars, just find a contractor who specializes in this stuff and pretty soon an automated voice will announce when the milk is low.

Fortunately, the rest of us aren’t completely left out of the home automation fun. But this stuff gets pretty geeky pretty fast, and it definitely helps to have some background knowledge about electronics and networking before diving in.

Why Automate Your Home?

Aside from the nerd bragging rights, fully-automated homes can be much more energy efficient. Left the light on in the basement after that last-minute laundry dash? That’s money out of your pocket. But an automated home could have killed the lights as soon as you came upstairs.

Ditto for the A/C you left running all night or the blinds you always forget to close in the afternoon heat. Your forgetfulness is wasting money and using energy you don’t need to use. Automation cuts down on your energy use by doing the smart and simple tasks for you.

Aside from the potential savings in money and energy, you can perform other practical tasks like monitor your pets, detect unwanted visitors or even send yourself an e-mail when the water pipes in your basement burst.

Using X10

For the DIY home automator, the most popular solution is the X10 network protocol. X10 is communications protocol and network address system not unlike the TCP/IP protocol that powers the internet.

The main difference is that X10 is very low-bandwidth. It’s able to use the power lines running through your house to send commands to your X10-compliant components. The basic set up is simple, and many X10 devices are quite cheap. A command center — typically a PC — sends messages over the wires and X10 devices respond to any commands you send.

Say, for instance, you plug a lamp into a common X10 wall outlet. Just set up your PCs with a serial X10-computer interface and you can control the light with your PC.

Using Software

Of course you’ll need a way to communicate with your X10 devices. Most DIY home automators recommend MisterHouse, a collection of open-source Perl scripts for controlling X10 devices. Not only is MisterHouse more robust than the software that typically comes with a serial interface, it’s Perl, so you can hack it however you like if you know the language.

There is also an elegant-looking home automation control center application for Mac OS X Leopard called Shion. It has support for Insteon devices (which aren’t hard-wired, making them great for apartment dwellers), uses Growl notifications and can schedule tasks through iCal. It even lets you use your Apple remote to run commands. It’s also an open-source app, so it’s hackable.

Another option is the commercial application Indigo. It is neither open source nor free, but supports the most INSTEON modules (thermostats, irrigation controllers, input/output controllers, etc.) and is extensible by both Python and AppleScript. It has has a graphical Ajax-based built-in Web server and has a very active user base and home automation discussion forum.

Further Reading

• Check out the MisterHouse site for more details and some examples of the things you can do with X10.

• comp.home.automation at Google Groups.

• Another excellent resource for the home hacker is O’Reilly’s Home Hacking Projects for Geeks.

• Here’s a link to an open source Zigbee software project.

Leave a Comment

Required Required (Will not be published) Optional Enter Your Comment

Add your picture!
Join Gravatar and upload your avatar. C'mon, it's free!