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PIR sensor help !! Answered

I have a PIR sensor.. initially when i tested it using an led.. the led used to turn on when it detected motion.. now it happens vice-a-versa . Any suggestions to rectify the problem?



Make my nightlight. You can also look up PIR sensor Parallax and use any code from Basic to SPIN to C to assembly. 

Transistor and relay and diode schematic.


Connect the end not connected to the PIR to the opposite supply - if you tied it to ground tie it to the supply instead. Don't forget the limiting resistor

There are 3 pins GND ,OUT,+5v
u mean i connect GND to +5v of the batter and so on?

NO !!!!

How do you connect your LED ????

If you connect it from Out to gnd, connect it from out to +5 and vice versa DO NOT REVERSE THE SUPPLY TO GND and +5V


well i tried it . anyways . i resumed my work using a transistor and relay.. works well..

thanks anyways Steve and Andy !!

I had a similar problem. If it is a PIR module, some of them have a jumper pin to make the output high or low on motion, it could be this. The correct set up should be 5v-+5v, GND-GND, OUT-LED-GND (possibly with a resistor in there so it doesn't damage the LED as I think the output is about 3-4v, but it should be alright just for quickly testing it).