Pyroelectric Infrared Detector LMI 878 I got this thing to sense motion. But I can't completely tell how to use it. It seems one pin gets power, another ground, and another is parallel to the power and creates variances in the source voltage to be measured. But I cant tell which pins for which and how exactly to detect motion with the arduino. I figure I use a resistor to get the voltage down to around 2.5v so that the analog in can detect higher and lower voltages. But thats just a guess.


O k look ground to arduino ground

D trough 10 k ohms to 5 volt in the arduino

S to the any analogue pin to the arduino

Im not really getting any coherent response. Should I be using something else between the arduino and the PIR or should this work?