PIR Sensor reset time?

CircuitMage

Looking at the datasheet and a quick forum search, I do not see a reset time for this Parallax sensor.

Does anyone know what this is? Approximation is fine.

And by reset time, I mean the time that it takes for the sensor to be used again (how long it takes to clear the state). When it triggers, there is a time for which the output pin stays high. On the datasheet this is with the jumper in the L position, allowing the output to retrigger when motion is detected.

Thanks

garyg

I set up my Parallax PIR sensor with jumper in L position.
It took about 40 seconds to warm up.
When I flash my hand in front, it takes about 3 seconds for the sensor LED's to turn off.
When I stand in front of the sensor motionless and then move, the sensor is triggered, If I stop all motion,
after about 3 seconsd the sensor turns off.
The sensor appears to stay on as long as the motion is detected, but as soon as it deactivates, it appears to be
ready to activate again.

It also seems that warmup time with the jumper in the S position is only about 20 seconds.
After that, I don't see any difference in the way it operates.

CircuitMage

Excellent information. That is what I was looking for. 3 second reset time.

I have also seen, in my applications, some retriggering on these types of devices. That is, while moving the sensor stays high (with hand in front of sensor), then when moving away the sensor goes low then hits high again for the minimum reset time. Not sure if you will encounter that, but just something I have seen on similar modules. No big deal, as the overall stability of the device seems good (no FALSE hits, just retriggers). I know if could be my power filtering, but it has not bothered me enough to really look at that issue.