I'm trying to get one of those cheapy PIR motion sensors to work but I am struggling.
I've gone through about 3 now and they all seem to die the same way.
The module is similar to this...
http://www.ebay.com.au/itm/HC-SR501-PIR-Motion-Sensor-Module-Arduino-Raspberry-Pi-ESP8266-/191621495655And from what I've been able to determine the module has a 3.3v regulator to power the board, a BISS0001 controller, and a 1k resistor between the Out connection and pin 2.
I want to drive a couple of relays, so I run the output directly into the base of a NPN transistor (PN100), emitter to ground, and collector is 12v + 1k resistor + LED, to start with.
The first problem is the LED never goes fully off.
So I remove the LED and run the output through an 800k resistor to ground and just measure the voltage - and it looks correct, about 3.2v when on.
Because I can't find any detailed data on what the BISS0001 output circuit looks like, I start playing around. Direct driving the LED from the output. I even tried using a pull up resistor.
After the fiddling, things start going really wrong. Now, the voltage on the output pin is showing 11v. Given the circuit runs on the 3.3v regulated supply, I can only imagine I have somehow toasted the voltage regulator. I have the current limited to about 50mA so I don't think it was a short.
So, I guess the first question is, does anyone know what is the output driving circuit of the BISS0001?