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help for PIR sensor — Parallax Forums

help for PIR sensor

boeboyboeboy Posts: 301
edited 2007-02-10 02:55 in General Discussion
Will the PIR sensor be set of by a cat?

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lets see what this does... KA BOOM (note to self do not cross red and black)

Comments

  • John R.John R. Posts: 1,376
    edited 2007-02-10 00:14
    If it (the cat) is warm and moves, it should set off the sensor, assuming the background is not the same temperature as the cat.

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    John R.
    Click here to see my Nomad Build Log
  • boeboyboeboy Posts: 301
    edited 2007-02-10 00:19
    Thanks, I know that some PIR sensors will not be set off by small animals but·I did not know about the parallax one.

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    lets see what this does... KA BOOM (note to self do not cross red and black)
  • FranklinFranklin Posts: 4,747
    edited 2007-02-10 02:53
    Most PIR sensors are sensitive enough to be triggered by a small animal in their view but it's the design of the device that keeps them form triggering. Some motion sensors have a mirror or shield that blocks low (physically low to the ground) heat signatures from reaching the sensor element. It's all in the design and intended use.

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    - Stephen
  • John R.John R. Posts: 1,376
    edited 2007-02-10 02:55
    Distance from the PIR to the "object" being sensed will have a significant impact on the size of critter than can be "seen". The closer the target, the bigger the "angular size", and the easier it will be to "see".

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    John R.
    Click here to see my Nomad Build Log
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