The nature of motion sensor

[rtrimana]

Hi everyone, just curious to know more about SmartThings’ motion sensors.
Does anyone know if they are sensitive to the motion of non living beings?
Or do they work based on body heat or something like that?

Thanks!

[GatVlieg]

Nothing to do with motion per se; everything to do with infra-red & heat signatures, especially in cheapo sensors. Heat a brick up in a micro & skid it across your motion area & it will trigger it…

J

[rtrimana]

I see. Thanks! So basically anything warm would trigger it.

[JDRoberts]

Yes. These are PIR (passive infrared) sensors which detect very small changes in heat moving across the lens. So motion is a part of the detection as well. Most of the home automation sensors are of this type.

See the following FAQ (this is a clickable link)

FAQ: Where to locate motion sensor for fastest response?

[image] I have a downstairs hallway that’s perhaps 12 feet long, with a doorway to a spiral staircase at one end (where the picture is taken from) and a door into the garage on the other end. As you can see in the picture, there’s a jog in the hallway. Not seen here are another doorway about 4 feet to the right of the one by the staircase, a bedroom door to the left at a 45-degree angle (you can just make out a bit of the trim on the corner of the wall, near the top), and a laundry room doorway on the right as you go through the jog. The hallway is dark and I want to automatically turn on the lights when I come off the stairway or enter from the garage. I have an Ecolink motion sensor and I’ve tried placing it in each of the four locations marked with circles. (The two near the top are …