I'm trying to replace the cheap piezo sound sensor on a halloween prop with a PIR sensor (HC-SR501).
The original piezo sensor used a 2 wire connector to the chip which I simply unplugged and replaced with my own 2 wire connector that I could use with the PIR. I assumed the + wire on the piezo was the one from the middle of the piezo.
On the PIR, I'm connecting the VCC to the power cord's red wire. GND to the location of the original piezo's negative wire. And the Output to the location of the + wire from the original piezo sensor.
Sad to say, it's not working. My multimeter says the PIR is sending about 3.3V of power thru the Output wire when I wave my hand in front of it. Then I see the Output drop to 0 after 5 seconds. But it does NOT trigger the prop.
Yes, and the PIR is typically used with an arduino board. I'm just trying to see if the PIR is able to be used by itself or if it has to be used with an arduino board, hence.... I came to the arduino forum.
I have the same question posted on a halloween forum, but I thought people on this forum would know more about the PIR sensor.
The PIR switches from 0-3.3v . Look at the spec of your other device to see if the output range is the same and can therefore be switched .
If it’s not the same then you can’t !
the piezo transducer will output sound signals which are ac voltage where the pir is a dc voltage.
does the pins from where the piezo plugged in go to a transistor through a capacitor.
if you put dc voltage into this it will stop conducting. but ac will flow through.
you might need to take this out and replace it with a current limiting resistor. but it depends on whether the transistor is constructed as a switch or an amp.
