Bare-bones PIR sensor

Hi all,

I am researching how to add PIR motion sensing to an LED light that I am designing. I know that there are many, many pre-built PIR modules out there but I want to start from the ground up to see what components I need and which ones I do not. My question is this:

What is the absolute minimum number of components that I need to create a functioning PIR sensor for an UNO R3?

Any help is appreciated :)

Find the schematics of a PIR module. Do you have a IR/thermal sensor already, can you detect the difference between both sides ? What about the lens, do you want to make your own lens as well ?

Hi Koepel,

I didn't realize that the IR sensor had a positive and a negative side but I guess that makes sense. I'm sure that I can find a way to determine which side is which. The lens helps the IR sensor to discriminate IR motion but I think if I just want a very simple sensor that can detect people a couple meters away I can do without it.

No, I don't think so. Not even 1 meter away. The sensor element has two areas, one on the left and one on the right. It measures the difference between those two, and that is what the lens does. When someone is walking, the lens makes that the two areas will get a different value.

Buy a few of those sensors and see what happens. They are only 50 dollarcents on AliExpress.

I have never used the bare sensitive areas to detect someone. I think it depends on many things, because a 'real' remote temperature sensor is not easy to make.

This is a 'real' remote temperature sensor : https://www.adafruit.com/products/1748