Like many of you, I use X-10 and HF motion detectors outdoors because they're cheap, mostly waterproof, run a long time on a set of batteries and have fairly decent range and they work. I find them very useful in helping me get to the front door in time to keep a "signatured required" delivery from turning into an "Attempted Delivery" sticker on my storm door. (-:
As those who own them probably know, they sometimes trigger at mysterious times for reasons that are difficult to explain. I bought the HF outside detectors on half price sale (under $10) just to test them, and they are pretty damn good. But like the X10 units, I was finding that they still went off in the middle of the night. To overcome this, I was hoping to incorporate the HF into my HomeVision home automation system so that I could "poll" both the X-10 and HF detectors to signal only but before I did that, I wanted to make SURE that the units were falsing and not actually seeing some sort of legit motion.
Recently, I was having false triggering so I bought a motion detector still camera like they use for nature photography for about $80 and - you guessed it - when set up to "see" what the motion detector saw I saw a frikkin' critter jamboree!
There was a leashless dog methodically making the rounds, running against the wall very stealthily by the side door where the kitchen is located. A big pile of dog crap and the strange behavior of my dog near the door should have alerted me that one of the culprits was canine. There's a pair of raccoons that make their way straight to the garbage cans and climb. There are birds that even swoop near the porch roof and right by the detector that set it off, although they never seem to stop on the porch - they use it as a pylon of sorts.
You can use a number of methods. A baby monitor connected to a VCR or DVR works nicely, too. When I had mice in the kitchen, I set out bait and left a DVR running all night connected to an IR bullet cam. One mouse amazed me by how deftly he snatched the prize - a pistachio nut - time and time again without setting off the trap. His string of luck ran out when I began to glue the nuts down with peanut butter. Fortunately, in proof that some good can come out of bad, the dog's finally had enough accidents all around the house that no more mice have come in. I'll bet they're not really accidents, but instinct telling her that her territory should smell like she does.
The videocam system is useful for precisely defining range. I have a little wireless job I got for about $30 that runs off a 9V battery and is much smaller than the battery(!) - I can set up the camera on a little clamp tripod to see what the MD sees, put the MD receiver near the camera's built-in mic and then just walk around. When you play back the video, you can see exactly where you begin tripping the MD by the sound of the buzzer. I've got it pointed to the street right now to map its activation zone - people at 75 feet but not (speeding) cars. I'm waiting for the garbage men to arrive - that should be a good test of sensor discrimination. HF occasionally gets some things very right. Hurrah! Slow moving school bus trips it . . . Whoops, it's the day after MLK's bday. All collections will be one day behind.
The treecam is really the best though - it's waterproof, self-contained, has IR lights, movie modes, runs on either 6AA's or DC - back when I did nature photography a similar setup would be huge, cost thousands of dollars and have nowhere near the capacity of a sub $100 unit. I just bought a 32GB card to see if it runs on one. I There's nothing like being able to sit at you PC, load the SDHC card into the reader and watching a high-speed movie of what happened last night. I'm betting you could make a pretty decent Indie film pointing it at the right places . . .
-- Bobby G.