[Solved] Bad sensor or bad setup?

Using Arduino General Electronics
#1

Hi all,

I've just received a PIR sensor I've ordered online, and I'm trying to test it with a basic circuit.
This is my setup:

The sensor is listed as "Model I052116", but the product description links to HC-SR501's datasheet.

What I'm hoping to happen is this: the LED is on at start, but it turns off, when I wave my hand in front of the sensor.

What happens instead is the LED is always on. If I turn the time delay potentiometer all the way counterclockwise, then the LED is flashing on and off.

Do I have a faulty sensor, or am I trying to use it the wrong way?

#2

Adjust the delay to a mid point such that it comes on and off as required.

Move a little at a time not all the way at once. Take your time with the adjustment.

Weedpharma

#3

These sensors have a time constant of several seconds - expect upto 10 seconds,
so wait for that length of time, then try triggering it.

#4

weedpharma:
Move a little at a time not all the way at once. Take your time with the adjustment.

Thanks! That helped a lot! Adjusting it patiently made me realize, that the output actually goes high on movement, and not the other way around.

With this in mind, I got it working in no time.

#5