If you're the geek parents of a car fanatic, maybe it's something like this. Another of my weekend projects, this video shows the homemade machinery behind the "Send Gavin a Car" car-launching feature of this web site. I brought it out of the closet for a little introductory video. To recap the original blog entry, clicking the "Launch Car Now" link on this web site will send ones and zeros from your computer all the way to the coat closet in our living room. A sound clip from the movie Cars will play, followed by a toy car shooting out from under the closet door into the living room.

For those interested, the "Launch Car Now" link triggers a bit of PHP script on the web server which sends an email to Traci's home computer (that happens to sit right next to the closet). When the computer's email program finds a properly coded email, it runs an AppleScript that pauses iTunes (if music is playing) and raises the volume to a level commensurate with gaining the attention of a hyperactive two-year-old. The script then triggers an applet I wrote in the Processing language. The Processing applet plays a sound bite of Lightning McQueen psyching himself up for the race in the movie "Cars". The applet then establishes a serial connection with the microcontroller on the car launcher (a Parallax Board of Education ) and sends a notice to launch a car. The microcontroller performs a bit of logic checking with it's sensors and switches while running the servo motor to open the launcher door (mounted to the garage section on a drawer slide) until one of my little black tabs interrupts the infrared beam to signify that the launcher door has opened exactly one garage bay. The car slides out into the excited hands of our son. Don't worry, video of Gavin running to the closet will come soon. You can watch Gavin's reaction in the Catching Cars blog entry. The car launcher then sits idle with the launcher door partly open until the next launch command is received, and continues in that manner until the launcher door is all the way open, at which point the launcher door closes and the launcher waits to be reloaded. The PHP script on the web server makes sure the "Launch Car Now!" link is only available during Gavin's normal living room playtimes, and also limits the number of launches to five per day.

Oh, and we do have coats in there, too.