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My PIR sensor continuously blinks the output when activated once, how do I fix this? Answered

I tried it on both settings (retriggerable and non) and it still does it.
am I doing something wrong?


It says it only has a TTL output, that isn't usually capable of driving an LED directly. You should try using a transistor to switch the load.


5 years ago

Please show the circuit schematic of how you are using it so we can talk to you about it.

Or a part number for the PIR sensor..


im using this, http://www.ebay.com/itm/1-Pcs-Adjust-IR-Pyroelectric-Infrared-PIR-Motion-Sensor-Detector-Module-New-/130617149865?pt=LH_DefaultDomain_0&hash=item1e696389a9

i have 4.5v going in and the led has a 200ohm resistor on it going from the out put to ground

That module is manufactured by Parallax  and here is the real data sheet
which looks like Rev_A.

If properly calibrated the output goes HIGH when movement is detected
and low when NO_Movement.
Rev_A that is output pin_3..
The output should drive a MOSFET like a 2N7000 available for 7¢..

The S wire goes to ground, the D wire goes to LED and resistor goes to any
voltage 4.5v , 5v , 9v or 12volt..  The Gatewire goes to the PIR output pin_3.


found it on new egg

If you click on the red word Parallax or this  it will take you to a deal on
an older revision  of A.

a 3904 seems to do the job! thanks so much for the help, took me a while to figure it out (i was quite tired yesterday).

would a 3904 transitor do the job?

that doesn't look like the motion sensor i have, and the pin outs are different

Check your power supply can handle the PIR without the voltage drooping.


Something is causing it to go off after it resets -- are you 100% sure there is no motion or heat signature?

yeah, it only stars blinkingg once a i activated it by waving my hand in front of it