electronic scarecrow

[sofaspud]

This is a junkbox-type project I've been brainstorming for a while, and I'd appreciate any ideas from this group.
What I would like to build is a battery-powered circuit that I can take camping. On those trips my food is kept in an ice chest or lidded plastic tub. Bears aren't a problem; for the most part this will be used to deter squirrels, raccoons, and possums. It needs to be capable of day and night use. I've only come up with either a microwave or infrared motion sensor, which would activate something like a simple small tethered robot (i'm imagining something with LED eyes that lights and crawls across the top of the tub) or something like a vibrating motor that uses the tub as a transducer of sorts, which would spook the critters away. I don't want bright lights and loud noise that will wake the entire campground.

[dacflyer]

a motion detector ...microwave or infrared sound like your best bet so far...
perhaps a base mounted motor...gearhead type maybe? and a crossbar on the shaft that will do a helicopter effect...with some shiny flashy tasels on it? ya know like theose used pom poms or kids bike handles...hmmmmm<p>it'd be silent for the most part...and you maybe could add a strobe light ??<p>anyway your on the right track

[haklesup]

IR would require several sensors for 360 degree coverage. PIR sensors (especially the 120V variety) are easy to find and relatively inexpensive. Are you willing to power it off an inverter. Standard floodlight fixtures would do the trick, just substitute the bulb with your scarecrow.<p>Microwave (like the kind used in car alarms) would be smaller and require only one unit but that single unit might cost more than 4 PIR sensors. On the other hand, it would run on low power and 12V out of the box.<p>Add a digitally recorded sound of a dog growling and you will have a sure fire critter scarer. Stationary red LEDs don't seem scary but a strobing bright blue one might be startling enough. Light gets attention, growling confirms the threat is near and eminent.<p>The Possum might just play dead rather than run if you are too intense and threatening. A Racoon may not be deterred by a dog if it is used to them and will soon learn that other tricks are bluffs but not in the one to five nights most people camp.

[perfectbite]

Or.......swing by the local zoo and get some Lion or Tiger urine (I have no idea how it smells to humans) and sprinkle it around the cooler before you bed down for the night. Dem liitle critters won't bother it. Bigger critters like Lynxes and Coyotes won't bother it either.

[sofaspud]

Might work, but then I'll need to ask for a way to deter that in-heat cougar. Not really the route I want to take.
I don't need 360° coverage. The sensor can be placed at one end of the container, so the coverage only needs to be ~45-90°. I had also thought of sound effects, but it was a rattlesnake rattle that came to mind. I figured there was a simpler way than adding audio circuitry.

[haklesup]

LOL "Excuse me sir, can you ask that Lion to pee in this cup" LOL<p>Digital audio is not too hard to add once you decide to make your own circuit Holtek makes some easy to use Voice chips. look at the Voice/Music section of this page. Minimal external components are required and can be breadboarded on generic prototype boards. With a typical 8kHz sampling rate for the EasyVoice the audio cannot contain too many high frequencies. A growl would reproduce better than a rattle I think. Some of the other chips offer better quality audio but are harder to implement.

[perfectbite]

"Soitanly. Here, hold my hat."

[Bern]

I don’t know how a very bright light would work. I have outdoor 150-watt floodlights on my driveway and in the backyard. They are connected to IR sensors, to light when people, animals, or what ever, come around. Just a couple of nights ago, about 3:00 in the morning, I happened to be where I noticed the backyard light come on. I looked out, and there was a raccoon under the light. Didn’t seem to bother it at all. On several occasions, I have seen raccoons, opossums, cats, dogs, wondering around under these lights, without any apparent concern.

[Bern]

I don’t know how a very bright light would work. I have outdoor 150-watt floodlights on my driveway and in the backyard. They are connected to IR sensors, to light when people, animals, or what ever, come around. Just a couple of nights ago, about 3:00 in the morning, I happened to be where I noticed the backyard light come on. I looked out, and there was a raccoon under the light. Didn’t seem to bother it at all. On several occasions, I have seen raccoons, opossums, cats, dogs, wondering around under these lights, without any apparent concern.

[toejam]

It seems that when tech was'nt so high, people protected thier food by hanging it from a tree branch.

[sofaspud]

What motivated that last response?? Certainly the tree branch is one way to go about it - that's cub scout stuff. Truth be told, the majority of replies to my post left a lot to be desired. That one, though, earns 2 badges for non-usefulness.

[sofaspud]

Here's my position.
I am here for just two reasons:
(1)to increase my knowledge on topics related to Nuts & Volts-type content
(2)to help others by passing along what knowledge I do have on Nuts & Volts-type content
Simple as that.
I do appreciate and thank all for their replies, but whomever suggested the "helicopter effect" gets extra thanks for that idea. That certainly is a simple, effective way of accomplishing what I want. If someone has an idea for the detector, they too could be assured of my gratitude.
Now on to the question, why not the tree? Well, I'm not ordinarily a backpack camper. Usually I'm camping in one of Texas' beautiful state parks. I can foresee a situation where there is not a suitable tree nearby, and I'd prefer not to make those trips back in forth. I could put the containers in my vehicle, but again the parking area could likely be many dozens of yards from the campsite. My idea for the project not only makes it more convenient for myself, but also for women and children that are along for the camping trip (I suppose a block and tackle would help in that case, but electronics is my thing).
There is no moderator here, and I'm for free speech and open exchange either way. It's up to each of us, and I personally would like to stick to (1) and (2) above. Thank you for your cooperation.<p>[ July 24, 2004: Message edited by: Morgen ]</p>

[perfectbite]

Is it my imagination or has civility given way to snippiness here? <p>I liked this forum because it was lighthearted, seriously informative and, although not truly a public forum, an open forum.<p>Lighten up.

[toejam]

a cactus maybe?

[jwax]

funk joined us, civility disappeared.