PIR sensor to detect pets?

SixOThree

I understand some infrared motion sensors are not good for detecting felines. I was hoping to use the PIR sensor to detect cats at a 6" to 2' distance. Anyone have experience with this?

Leon

Where did you hear that?

Leon

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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

SixOThree

I heard it on the google.

"Pet immune" is a selling point for infrared motion detectors used in alarm systems, that your pets won't set off the alarm. Sometimes selling points aren't features but just something inherent in the technology. Cats wear fur coats, have different body temperatures, and radiate heat differently; So I suppose the question is valid.

SRLM

I don't think that is the reason. According to this site, a cat's body temperature is higher than a humans, leading to more radiation. And what about humans wearing coats? Is is any different? I think pet immune sensors calculate the size of the object, and don't trigger below a certain threshold. The parallax PIR is really sensitive, and it can easily sense some very small body parts (hands) at 6 feet + (as I remember).

SixOThree

Thanks that's exactly what I need to know about it. And I wasn't suggesting it wouldn't work. I was just pointing out the reasons I had for questioning whether it should or would. But since we're on the subject, I found this.

Post Edited By Moderator (Chris Savage (Parallax)) : 2/6/2009 5:36:17 PM GMT

Ugha

Hmmm... Think the PIR will pickup chickens? [noparse]:)[/noparse]

I've been wanting to install a motion-sensing camera in my egg house for a while now to tell which hens are laying and which will... ahem... end up in the freezer.

Franklin

Ugha, perfect use for rfid. If chicken A was on nest 6 and no egg exist chicken A = dinner

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- Stephen

$WMc%

SixOThree

PIR has been used with security systems for years, not to mention motion lights.

A CAT is warm blooded and gives of heat.

The use of a PARABOLIC reflector will give You the added gain needed to make the circuit work.
Forest M. Mims III demonstrated this back in the 80's ,the use of a flash light reflector and placement of the IR transistor.

Look at the reflector (It will be all silver) and now slowly insert the PIR device into the reflector (were the lamp would be). A figure "8" will start to form on the reflector,When the reflector is all or mostly the color or the PIR device,·The PIF device is in focus.

If You experiment with this a Little, You'll see what I mean.

Use a IR Transistor and not a IR detector.

This will work with chickens as long as You buy them their favorite chicken feed.


______________$WMc%________I like CATs____They taste just like chicken_____________

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The Truth is out there············································ BoogerWoods, FL. USA

Post Edited ($WMc%) : 2/7/2009 4:42:43 AM GMT

Phil Pilgrim (PhiPi)

I have a PIR sensor in my shop as part of an alarm system. A couple times, a mouse has gotten into the building, which triggers the alarm. It's a real nuisance when that happens, because I can't set the alarm again until I catch the mouse. Another thing that triggers it is the fan on the heater. Just the movement of warm air is enough. So a warm-blooded pet should be no problem to detect.

-Phil

Tracy Allen

I think the "pet immune" feature has to do with the field of vision of the lens, which is purposely kept above the animals normal height. On the other hand, PIR is used quite often with a different purpose to trigger wildlife cameras. We have used it in a project to gage the activity of bats as they sortie from their roosts.

We have a mouse we need to catch... hmmm

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Tracy Allen
www.emesystems.com