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Movement Sensor

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jsjackson

New Member
Hi All

Im looking for a device like a PIR but not infrared, I just want it to detect when something has moved passed it! the distance is no more than 2cm really

A PIr is is perfect but it detects heat movent I just want to detect movement

e.g

if move a pencil or any other object past it it will detect that some thing has moved past it


:confused::confused: can any body help me
 

colin55

Well-Known Member
A PIR will not detect a pen or anything that does not have a temperature of about 35 degress C.

If you fully cover yourself with a box and walk around a factory or shop that uses PIR's, they will not detect you.

I use it all the time to rob liquor shops. I have some cheap wine, beer and spirits. All 10% of normal price. Just give me a call.
 

colin mac

New Member
A PIR will not detect a pen or anything that does not have a temperature of about 35 degress C.
Source?

My PIR sensor circuit is on the table and the pen I throw past it is nowhere near 35 degrees C.
Passive InfraRed sensors (PIR's) are electronic devices which are used in some security alarm systems to detect motion of an infrared emitting source, usually a human body. All objects, living or not, whose temperature is anything above absolute zero (-273.15°C or -459.67°F) emit infrared radiation. This radiation (energy) is invisible to the human eye but can be detected by electronic devices designed for such a purpose.
NationMaster - Encyclopedia: Passive infrared sensors
 
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colin55

Well-Known Member
Your circuit may be dual detection. Both IR and photocell. That's why they introduced dual detection. Because IR was so unreliable.
 

colin mac

New Member
No. Just a PIR sensor under the Fresnel lens. It came with a photocell that could be added alright.
 
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Diver300

Well-Known Member
Most Helpful Member
PIR sensors have a single sensor.

The lens in front of them focuses infrared light from bands in front of the sensor, and not from others.

As someone moves in front of the sensor, they move in and out of the sensitive bands, so the amount of infrared goes up when the person is in the sensitive area and down when they are not. The change in infrared is what triggers the sensor.

That relies on the person emitting a different amount of infrared to the background. If the person is at the same temperature as the background, the sensor won't work. There is nothing special about 35 deg C. Anything moving horizontally that is a different temperature from the room will set off a PIR.
 

pandu2288p

New Member
i want human movement i.e. forward ,backward,sidesteps on stage
it will be communicate with AVR or microntroller.
so can i use pir sensor or any other devies????????

Pleaze help me?????????????????
 

Sceadwian

Banned
The ping sensor will only tell you the distance to the closest echo'ing object, it will not tell you if the object is moving forward backwards left or right. Tracking a human being like that is no easy task.
 

Mike_2545

Super Moderator
The ping sensor will only tell you the distance to the closest echo'ing object, it will not tell you if the object is moving forward backwards left or right. Tracking a human being like that is no easy task.
True. But the OP wanted something that could detect objects minus the heat. The forward, backwards and left, right is from someone who hijacked the thread...
 

Sceadwian

Banned
Well that's what I get for not reading all the posts in a thread =P Damn hijackers.
 

pandu2288p

New Member
i want to track human movement on stage where light system & sound system is avalable ........
hence i want track every movement (means forward ,backward,side-steping) without distrubing these systems:confused:
in my project there are 2by2 meter demo stage.
so i want not only 2by2 meter becose not only for demo .

if we able to track step then we have to communicate AVR series and handel differently events on basis of movement.
pleaze help me??????????
 

Sceadwian

Banned
You could use a camera mounted high above pointing down and use IR LED's as beacons, but you'll have to plant this on the actor so that no matter what direction they're facing the beacon is always visable.
 

Mr RB

Well-Known Member
You could put those little reflector buttons on your actor, then shine high powered infrared at him and use an infrared filter on the camera. That way it will ignore most of the light conditions from your stage lighting spotlights etc.
 

Sceadwian

Banned
IR beacons on the actors are going to be smaller and WAY brighter than IR reflectors from ir flood lights. IR floodlights are ungodly difficult to build at any significant wattage. Simple LED beacons are almost trivial, but keeping one in view at all times is the hard part, would be the same with a reflector.
 
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