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Automated Sentry Robots
jimbob5 writes "New Scientist reports that you can now buy your own automated Room Defender. 'Who would like this gift? Any child, or anyone who saw the director's cut of Aliens and dreamed of owning one of those automated sentries.'" The New Scientist gift guide looks pretty useful.
I've wanted to build one of these things for years. However my goals were a little higher. Complete motion tracking camera/servo system, and it would have fired paintballs or airsoft BBs... Too bad I never thought of the downgrade to common toy as a great selling point. Guess I'm and engineer and not a businessman.
They've had them since I was a kid. There were little motion alarms, something that shot ping pong balls, etc. I built one of these in my high school electronics class - the assignment was to wire a "home security" system to the user port of a C64, the home security system was then installed in the framing of the "house" that the wood shop students would build, then tear down every year.
We wired up an electronic valve attached to an air compressors tank, and it would blast "invaders" in the face with air, and a sparker right in front of the nozzle. As you can imagine, we weren't allowed to use acetalyne.
This is a pretty chinsy looking toy, a plastic piece of shit that shoots foam disks. There's no technology there to be interested in. Oooh ooh a motion sensor! Buy it for christmas, its broken by new years.
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I don't need no instructions to know how to rock!!!!
Put down your weapon. You have 20 seconds to comply.
A group at my university built a similar sentry robot, but armed with a soft air gun, two years ago for an electronics project... all you would need to do would be to exchange the gun replica for a real one :)
As it is, it appears to be little more than a light sensor attatched to a rapid-fire nerf gun. i.e. Dumb-fire, no aiming.
These are still quite fun. You can buy the pressure-hose equivalent from hardware stores to keep raccoons/cats/etc. away from your garbage, flower garden, or whatever.
I was quite impressed when I saw one of these, though in hindsight it's just a combination of two widely-available existing devices (automatic sprinkler and motion-sensor light). Impressively elegant.
So,
My parents had a flower bed that the neighbourhood cats used as their litter box.
Dad got fed up with that and built a little contraption.
He rigged up a booby trap with a wire and a clothes peg. When the cats tripped the wire the clothes peg pulled off and broke a circuit with a battery and one of those old style magnesium flashes that one used to have for cameras in the 70s.
So the cats would walk in there at night, with pupils dilated to the size of grapes and preparing to do their business.
And trip the wire and.... *flash*!!!
The wire got tripped a few times. Once per cat in the area I would presume. And then never again.
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Freeze the scene in which Cpl. Hicks sets up one of the Sentry guns with an amber-screened laptop, and you'll get an idea of James Cameron's fanatical attention to (convincing) detail - the sentry guns have all sort of settings for "Interrogation modes" "IFF (identify friend or foe)", and an expected target profile, "Soft, Hard, semi-hard." Very cool stuff, but the theatrical cut didn't suffer too badly without that and other scenes. Two of my favorite films, Die Hard and Aliens were long (2.25 hrs apiece), but felt much shorter because of excellent writing, directing and a smoothly flowing storyline.
Check this out. It uses a camera to track its targets. http://jpbrown.i8.com/aegis.html
Yes Francis, the world has gone crazy.