Can I lower the delay time for the HC-SR505 PIR or force it low with a command?

Is there a way to do what it says in the question please? Maybe attach a potentiometer like the HC-SR501 has?

Or will forcing the pin LOW force the sensor to go low too?


There are two pots on that PIR sensor. "Time" and "Sensitivity".

The "Time" pot should be fully anti-clockwise. That will give a minimum "ON" time of ~2-3seconds.

A longer delay or re-triggering should be done with the Arduino.
A shorter delay than 3 seconds can't be done without hacking the PIR circuitry (the "time" cap on pin4 of the chip).

The "Sensitivity" pot is AFAIK not distance sensitivity, but a trigger delay.
Leave it in the middle.

Thanks, but I’m referring to the HC-SR505, not the HC-SR501

Please note that I did try forcing the pin to go LOW with digitalWrite(pinnumber, LOW) and it didn’t work.

Looked at the diagram for the 505, but all web pages and pdf files I could find for this sensor show the wrong diagram (16-pin chip). Can't find any usefull information for this sensor (with an 8-pin chip).