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Do I need a microcontroller to use my Parallax PIR sensor? Answered

 I linked 4AA batteries, 330ohm resistor, red LED, and the PIR (with ground going to ground) but the LED stays on no matter what. 

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thegeekeBest Answer (author)2011-10-01

Yes. I have the same sensor, you need a microcontroller for it. If you're new to microcontrollers, look for a microcontroller starter pack. There's some pretty nice ones out there that are a decent price.

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andy70707 (author)2011-10-02

Not necessarily, you can get some propriety logic devices for PIR sensors. I have used the BISS0001 in the past (available on eBay), and you can also use some transistors and resistors for some sensors. One sensor worked with a simple current-limiting resistor and a 2N3904 transistor.

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thegeeke (author)andy707072011-10-02

Hmm... interisting. I've only been able to get mine to work with a microcontroller.

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AndyGadget (author)2011-10-02

 
NO - You don't. (although you can use it with a microcontroller.)

The DATASHEET gives you the pin and jumper functions.
It doesn't mention it here, but I'm sure the output is good for 20mA so you can drive your resistor / LED directly.  Are you leaving enough time for settling?  These things output a high for a good few seconds after turn-on.

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