Room presence methods

#1

Hey all,
I’ve been looking for a good way to see if someone is in a room or not.
And i think i’ve found a fun way for my bedroom.
I’m going to use radar sensors and pressure sensors to detect if someone is there.
The radar sensors are going to be for detecting movement in the room.
The pressure sensors for the bed, to see if someone is laying on the bed.

I was also thinking of trap wire lasers to sense if someone is going in or out of the room. You could also count the amount of people in the room. But this will need a bit of wiring and i really wanted a compact solution.

I was wondering how you guys are doing it.
I don’t want to use annoying timers and stuff to turn off lights.
The motion sensors from Smartthings are really annoying, randomly sensing motion and stuff.

#2

I’m doing this with a combination of regular sensors.

Motion Sensors - Someone has moved recently
Power Meters - If the TV/Computer/… is on, someone is likely in the room.

With the power meters, you can track what your TV uses while watching TV, Netflix, … and what it uses after being paused for 5-10 minutes.

For example, if the TV’s power drops below 170 watts and all motion sensors are inactive, then no one is in the room.

I have a couple pressure mats to detect someone sitting in certain cases.

Also, pro-tip! If you put a Motion Sensor that has a temperature sensor in it above a TV, you can tell if the TV is on based on the temperature rise. It’s not as accurate as a power meter, but it will work where you don’t need the accuracy. Same thing for a Motion Sensor in a bathroom with a shower (if it’s close enough).

#3

Do you have a link for the pressure mats and power meters? I’m wondering what kind they are. I’m just using arduino’s for these things right now. But how long do you keep your lights on? Because there won’t be always motion and it could be there is someone there without using the TV.

#4

I have two pressure mats.

This one will take at least 25 lbs to set it off. This one just takes around 5 lbs.

You have to cut the wire and connect it to a contact sensor that has external contacts like this one.

This is the plug I use that has a power meter built in.

When it come to deciding how long to keep a light on, it depends on what people do in the room. If you sit and read you won’t have a lot of motion, but you should have some every 5-10 minutes. So keep the lights on at least that long.

#5

Thanks! I’ll try some stuff.