What is the MAX length for PIR sensor ?

[milan.rajik]

What is the max length of wires that can be used with a PIR sensor ? My PIR sensor is from Parallax. It has 3 pins. Vcc (5V), GND and OUT. Out pin goes high when motion is detected and remains high as H_L jumper is set to H. They are 5V TTL pins. I need to know the max length of wire that can be used to interface this with PIC18F MCU. In my system I will be using 3 PIR sensors. One will be near the main board and others will be at different places but with in 10 feet radius.

 

[Ogu Reginald]

Firstly, the max length of most PIR sensors is 20ft. I don't think there is a limitation to the length of wires to be used for PIR interfacing provided the wires are in perfect condition.
And also I have checked the datasheet of the PIR sensor I use and I can't find any information concerning the maximum length of wire to be used.