"Christmas Light Hero is using 7 light controllers from Light-O-Rama built from kits to control 21,268 lights and LEDs. Each controller has 16 outputs and 2-3 TTL level control inputs that are used by the game system to fire different programmed light sequences depending on what happens in the game. It relies on the fact that the game sequence is very consistent. If the game and the lighting sequences start together, they will stay in very good sync through the length of the song. The light program allows branching and overlays for fail, star power and "ready." I have some ideas to automate the initial show/game sync, but for now you have to push doorbell buttons at the right moments.
To program the show a video recording was made of a perfect round of Guitar Hero playing Eric Johnson's Cliffs of Dover. The timing of all the dots and the light show choreography follow that video.
When you play, you watch only the Christmas lights, but the audio you hear is from the Wii, so your flubs are broadcast for all to hear (people in cars can tune 99.1 and crank it up as loud as they want.) When we are not playing, a separate version of the program that has the audio from the recorded game plays with the lights as a loop. The YouTube video also has this audio, (because I forgot to record the direct audio when I was shooting the documentation, and the camcorder did not pick it up very well.)A video screen is on the driveway showing the game video, but if you want to be on the high score list you have to make it through the whole game only watching the Christmas Lights. Even though the game is in "easy" mode, the lights don't provide the same timing detail as the game does, so it is much harder. Even expert Guitar Hero players have a hard time with the lights, and nobody has made it through without errors (yet)."