Wednesday, April 20, 2011
The Nefarious Mister S (part 2)
So how do you nail someone who's been throwing trash in your car? Over the next few weeks I thought it out. It would have to be something reasonably cheap (minimum wage) and easy to set up and hide, since a Tracker's not exactly secure. The rear window hasn't zipped up since I unzipped it--the day I bought the car. All that's holding it up is a bungee cord sewn to the "glass" panel and de-barbed fish hooks sewn in several places around the opening. Mister S was dropping his trash through the gap on the left.
I don't remember what triggered the Big Idea, but in mid August of '07 it hit me: a small camera with a motion sensor. I found several online, but nothing affordable...so I'd have to build it myself...but first I had to wait for payday.
RadioShack had exactly what I was after: a cheap digital camera and a motion sensor. As soon as I got home from work, I went over each of them and made notes. Camera's battery powered...one "AAA"...turns itself off after 1 minute of inactivity...can't be set to stop doing that...two buttons (Power/Mode, Shutter)...motion sensor takes 9 volts...alarm can be silenced...no output that could trigger the camera.
Ponder, ponder, think, think...need a circuit that will "listen" for a signal from the motion sensor and trigger the camera shutter AND a circuit that just pushes the camera's Power/Mode button a few times a minute to keep it awake. Okay, dig out some electronics books...find something close to what I need...throw a prototype together...modify the camera and sensor...test, fix, test, fix, test, fix...build the board...by September 10th it was all together, part of the camera and the sensor painted yellow to match the Tracker. Everything was powered by a block of "D"-cell batteries: 9 volts' worth for the sensor and circuit, a single for the camera. I was pretty proud of myself.
The plan was to hang the camera where it could see the Tracker's rear window. The sensor would be mounted so that it could pick up Mister S's hand entering the car. Click! I got a few test pictures, set the rig up, and left it to itself.
Didn't catch a thing. There was new trash in the car, but no new shots in the camera. I tried for more test pictures and realized pretty quickly that the infrared sensor was getting washed out by sunlight. Unless Mister S was kind enough to put his hand within an inch of the sensor (or wait until dark), it would never trigger the camera.
Well, crap. I had to think up something else.