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July 27, 2009 AT 3:06 pm

PIR (motion) sensors in the shop!

Pirsensor Lrg
Pirsensorback Lrg
PIR sensors are used to detect motion from pets/humanoids from about 20 feet away (possibly works on zombies, not guaranteed). Usually this sensor comes with a straight 3-pin header soldered on. This makes it annoying to use because its is not easy to plug into a breadboard and you can’t solder wires in. So we requested to leave it off and include a 3-pin right-angle header instead which you can solder in for breadboard use or skip and use wires. Runs on 3.3-6V. Digital signal output is high/low. In the shop now, $10 !


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7 Comments

  1. I’m currently building a wildlife camera trap for a nature museum using the Parallax version of this sensor. but I believe it functions identically. It is very easy to hookup and get functioning with a few lines of code. Depending on the size/IR strength of the target, the sensor has a range upwards of 40ft- ymmv. The datasheet also says to give the sensor up to a min to calibrate, but I have found 5-10 seconds after powering up the unit, and no motion in its field of view, that it has settled and works fine.

    Its definitly a fun little sensor.

  2. Can you adjust the sensitivity? I’ve been hacking the commercial motion sensors for light fixtures because they’re adjustable. This would be smaller and much easier to work with…

  3. I found this for the Parallax PIR sensor module:
    http://www.neufeld.newton.ks.us/electronics/?p=208
    I suspect the IC onboard which does the signal amplification and TTL conversion can be modified in a similar fashion. Or, you could build the whole circuit yourself with the D203B module this board is built around.

    But the beauty of this board is that it’s all put together for you.
    You could play around with shaping the field of view and your program code to create levels of sensitivity based on duration of detected motion.

  4. Thanks for that tutorial! The lens is fixed, so you cant change the range or sweep. Unfortunately this sensor seems to be one of the only ones that is easily available for microcontroller hacking. I wish there was better but the factory was not very receptive to improvements :(

  5. Did you mean “easily available for microcontroller hacking” or “not easily available for microcontroller hacking”? I ask because the statement makes more sense with a “not”, but I thought I should ask. Funny how one word can mean so much to a statement. :)

  6. i do mean, this is one of the easier ones. most require 9-12V. this one is 3-5V logic. that is unfortunate because i wish more (better) sensors were microcontroller-compatible

  7. This sensor is digital. If you need adjustable sensitivity you could create a formula that only would trigger if say the last 3 of 10 readings came up positive. Therefore disregarding rogue positives.

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