PIR object detection sensor

Technic-R-C

Hello

I have found a PIR object detection sensor in my tool box and I am kind of confused about the wiring.· THere are three cables coming out of the sensor.· One is labeled GND (ground), another PIRS, and another PIVS.· Does anyone know what the PIRS and PIVS mean?· I am guessing that the PIRS is the signal cable which connect to a BS2px I/O·pin while the PIVS connects to the VSS pin.·· However I am not sure and do not want to ruin the device or my BS2px.· Can anyone help.

Thanks

Technic-R-C

Mike Green

How about looking for the corresponding documentation? If it's a Parallax sensor, it comes with all sorts of documentation which would be downloadable from the Parallax webstore page on the sensor. If it's not Parallax's, it's anyone's guess. Your guess doesn't sound very promising since Vss is usually used to refer to ground (Voltage - SubStrate)

Technic-R-C

I've checked for documentation and there is none on the web.· The number on the PIR sensor did not appear in any searches.· Would it be possible to hook up the PIR sensor safely without damaging either the sensor or the BS2 to test it?

Technic-R-C

Technic-R-C

WHen looking at the Parallax PIR sensor I noticed that the 3 pins alligned in a row kind of match up. (here is the link to the·circuit (1st page))· The top is the VSS port, the middle is the GND (Vdd) and the bottom is the Output.

Parallax··· mine
VSS -->·· PIRS··· top
GND -->·· GND···· middle
OUT -->·· PIRV··· bottom

Is this correct considering I have nothing else to go off of?

Technic-R-C

Mike Green

Repeat after me ... Vdd is the positive supply voltage. Vss is the logic ground. There are special case rare exceptions these days, but you won't find them in any modern logic circuit.

Without some kind of documentation, there is no easy way to hook up the PIR sensor without taking some risk in damaging it. You can protect the BS2 by using a 220 Ohm resistor in series with any I/O pin you're using. You're probably right that PIRV is the supply voltage and PIRS is the signal line, but there's no certain way to test it. I would probably put a milliAmp meter in series with PIRV and, using a variable voltage supply with current limiting, gradually increase the voltage towards 5V while watching the current drain. If it stays below a couple of milliAmps, then it's probably right. I'd then put a logic probe or voltmeter on PIRS and see if it switches when I move in front of the PIR when power is supplied.