Surprise! Free Hacked Gadgets!
This past Friday I received a large package from FedEx that I wasn’t expecting. It was clearly addressed to me, but it had a New York City return address that I didn’t recognize. Being a man possessed of a powerful zeal for adventure, I promptly opened the box.
It turned out to be a mutilated disposable camera, a basic pc microphone, and a tape recorder with the cassette door removed. The camera had a small electronic component soldered to its circuit board and spliced into a 1/8″ audio cable.
Although I had a pretty good idea of what this pile of junk did when it was all connected, I didn’t know who had sent me this mysterious equipment, or why they had done so. I poked around in the shipping box and found a contest card from Popular Science that I had filled out at the Austin Maker Faire in October. There was no other information about the stuff or why it had been sent to me. After a bit of looking about, I found a blog entry detailing the process of disassembling and re-purposing the very devices that I had received.
Here’s a basic explanation of what all this stuff is for. The microphone is connected to the tape recorder’s input. When it picks up a sound above a certain volume (say, a loud percussive sound), that sound is sent as voltage out of the tape recorder, through the cable spliced to the camera’s circuit board. This tricks the camera into thinking the shutter has just been activated, and it fires off a flash. To make this useful, set up a light-controlled environment and make it as dark as possible. Then set up a camera for a long exposure and take your shot, making sure that whatever you are doing to trigger the flash takes place before the camera shutter closes. Ideally, the sudden, audible event (a balloon popping, a bullet firing) that triggers the flash captures a very brief moment in time that would otherwise be hard to see or capture precisely with the shutter release.
I needed to try this out. I fetched some batteries, set up the little Canon Powershot for some 2.5″ long exposures, turned out the lights, and brandished my confetti revolver.
Unfortunately my camera doesn’t have a manual focus mode, so it was hard to get sharp images. I brightened up the images somewhat so details are more clear. You can see whisps of heated confetti shrapnel popping out quite far from the gun. You can also see the light from the exploding charge passing through the rear of the confetti gun’s plastic shell.
Suzie on the trigger:
Here, I connected a different microphone directly to the handle of a sauce pan filled with water. I tossed in a little squirty toy and the sound trigger picked up the moment of impact with the water, rather than the splash:
Here’s a Youtube video showing the flash kit in action:
My thanks to the folks at Popular Science for sending me this fun little assemblage. I very rarely win stuff in contests, so this was a pleasant surprise. Although I could certainly spend some more time calibrating the Powershot, I’d like to try this with a more responsive SLR to get the best photos. Different sound devices can be used to generate different results and trigger speeds, and timing or delay circuits can be added to the camera’s flash for further control. If you don’t feel like rummaging around or dealing with ebay or craigslist to find the components, Make sells a kit to build your own flash controller box, and there are plenty of plans around the interweb for building one yourself from scratch.