Hi there!
I am in the situation where I need a PIR motion sensor with no delay time and without a "blocking time" as well. Right now I am using an Arduino uno and a PIR motion sensor HC-SR501. When I got it, the signal turns high for about 2-3 seconds (when it is set to minimum delay), which is followed by a blocking time for about 5 seconds. I wanna use the sensor in a project where I need the signal to be able to turn high and low many times in a row in short time, therefore the 2-3 + 5 seconds makes it way to slow.
I am not an expert on soldering or electronics in generel, but after a lot of research on the web I found a method that should solve my problem - by removing specific resistors on the sensor you should get rid of both delay- and blocking time. see youtube link.
I succeeded in removing the resistor that should take away the blocking time, and yes! the 5 seconds of blocking was suddenly gone! big improvement. But when I did the exact same thing with the resistor that should take away the delay time nothing happened... I have tried this with two sensors, both HC-SR501, but bought different places and still no result. I have marked the succesful hack with green and the other with red - see images.
I am starting getting real dizzy from researching about this without getting any breakthrough.
So does ANYONE has a solution to this? Or know about a sensor without this issue? .
Any help is very much appreciated!