History of the Show
In December 2005 an engineer friend of mine showed me a movie of another house that had computerized their Christmas lights, and that is what inspired me to do this project. This video blew me away when I first saw it, and I thought to myself ... Wow - I would like to do that ... I think I can figure out how to do that ... I KNOW I can figure out how to do that ... You can download that original movie, which is of a house up in the Chicago area.

I started work on the project in February 2007 and built all of the hardware and wrote all of the software myself. In December of 2007, I had my first show. It was only one song, Angels We Have Heard on High, and there was no control box at the sidewalk. The lights couldn't fade, and there was no radio broadcast. In other words, the show was only half of what you see today.

In 2008 I worked most of the year to add the ability to fade lights, select the songs from the sidewalk, etc. So basically what you see today is the result of a two year project.

About
There are 2400 lights on the eave of the house. There are 16 segments, each of which has 3 strands of lights, 50 white, 50 red, and 50 green. There are probably about another 6000 or so in the yard. As far as big yard displays go, that isn't a really big number. I use the computer control to get more "Wows per Watt" - and therefore it's good for the environment. ;-)

There are 140 different channels of control. Each channel is one string or a set of strings of lights that can be turned on and off independently by the computer. The computer sits in my garage and has control cables out to 19 different subcontrollers around the yard. The computer plays the music digitally, so that the timing is precise. At the same time, it has a sequence of commands to turn sets of lights on and off.

The music plays automatically every half hour beginning at 6:00PM and ending at 10:00PM. If you want to play a song on demand, there is a user console next to the sidewalk with two buttons. The orange button lets you select which of the three songs you would like to hear. When you press the green button, the song will play immediately.

In 2008, the computer counted 542 times that the Play button was pressed to play a song on demand. In 2011, Play was pressed 880 times.

For engineers and geeks only: I have a technical page on how it was all done, plus a HOWTO on computerchristmas.com which is where I got the design for the main controller.

I gave a talk at the South Florida Linux users group about how I did this project using Free and Open Source Software (FOSS). For the technically inclined, the slides from that presentation are still online at flux.donlaw.com.