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Motion sensing with a PIR sensor (FreeBird - Part 3)

October 15th, 2007 · 6 Comments

Passive Infrared detectors are used to sense motion. I am right now experimenting with such a device from Parallax. For once, this is a sensor which works with 3.3V, so the interface with the AVR32 processor is simple. Whenever movement is sensed, the output of the device goes HIGH and then LOW. Placing an LED on the output pin (buffered by a transistor) makes this `sensing’ visible! Watching the LED light up and go off in a dark room as you move around the sensor is kind of spooky! Now, what kind of application can this have on a FreeBird?

Watch the PIR sensor in action!

Tags: Electronics · FreeBird

6 responses so far ↓

  • 1 Anonymous // Jan 8, 2008 at 9:49 pm

    good for office cube so nobody can sneak up on you

  • 2 Anonymous // Jan 16, 2008 at 5:48 pm

    can u caunt the frequency of oscillation with it?
    can it give that sort of fast response? and is it able to locate a marking on an otherwise plane surface?
    for example, can it sense a line on a wall which is otherwise featureless?

  • 3 ej // Jan 16, 2008 at 5:48 pm

    can u caunt the frequency of oscillation with it?
    can it give that sort of fast response? and is it able to locate a marking on an otherwise plane surface?
    for example, can it sense a line on a wall which is otherwise featureless?

  • 4 Pramode C.E // Jan 20, 2008 at 5:51 am

    Hello ej:

    The PIR sensor is NOT for line sensing - other simpler
    modules are available for that.

    I don’t really understand what you mean by `frequency of oscillation’. Maybe, you mean an object is moving in front of it in a periodic manner (like a pendulum) and you want to measure the frequency? If that is the objective, I don’t think this
    sensor would be able to do that also …

    One link which you can check out:

    http://nsc.res.in/~elab/phoenix/

  • 5 ishani // May 7, 2008 at 5:10 am

    i am workin with atmega16.and want to interface PIR with it..so PIR can be directly connected to avr?

  • 6 Pramode C.E // May 7, 2008 at 5:30 am

    Yes!

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