Home automation with X10

Posted by Steve on Wed, 08/23/2006 - 8:48pm

X10 is a powerline protocol which lets X10-enabled devices communicate with each other over your household wiring.

An X10 device could be as simple as a remote control for an existing entry way light switch or it could be a complex network of X10 devices remotely controlled by a PC which automatically sets lighting schemas, waters the lawn, sends a text message, feeds the cats, whatever, based on the time of day or some other external event.

Graphic courtesy of X10-store.com home automation.

I was introduced to X10 by a film maker friend who had a weekend house in upstate NY. On Friday nights, when he was about an hour away from arrival, he popped open his cellphone, "called" his house, typed in a code and a few commands and, presto, the X10 thermostat in the house was reset from 50 degrees to 72 degrees and the hot water heater was turned on. When he got to the end of the long, dark dirt road to his house he used the cellphone again to turn on the outside spot lights. His house would even call him if the X10 security system was triggered or if the inside temperature dropped below 45 degrees.

To say the least, this really appealed to my geeky side. I had to have it.

My installation isn't nearly as ambitious as his, although with the diverse assortment of X10-compatible devices available it's limited only by your imagination. You could, for instance, install X10 solenoids to close the living room blinds when the temperature in the room rises above 78 degrees or an X10 moisture sensor in your tomato garden to tell another X10 device in your micro-irrigation system to get to work. There's even an X10 device that plays the digitized sound of a pair of nasty, snarling dogs in response to an X10 motion sensor.

About 80% of my household lighting is under X10 control. From my Linux box I can turn them on and off and even dim them remotely. It also means that that they can be automated further by having them run under Unix's cron scheduler. For instance, my house "knows" when it's thirty minutes before sundown in my locality and turns on the porch lights, the entry way light and the upstairs sconce. At midnight, it kills the outside lights, the accent lighting and dims the entry and upstairs hallway lights by 50%. It also makes sure I turned off the garage and basement lights by sending them an "off" signal.

Next to my bed I have a whole-house X10 controller. When I hit the sack I don't have to worry about whether or not I left a light on in the house. I just hit the ALL OFF button and X10 kills everything for me. Similarly, if I were to hear a noise downstairs I could hit ALL ON and light up the house like the Port Authority bus station. But my dogs would be on the case long before that.

This is an introduction to X10. I'll talk more about it in future articles, including its problems, post some HOWTOs and discuss some of the more modern home automation alternatives.