Motion Sensor to turn light on? How does this all work?

Hello Everyone,
I’m brand new to the SmartThings world and I need a little guidance.
My goal is to turn on a light in my room whenever someone climbs up the stairs to my floor.
My first question is- How is it all connected? (How can I tell the light to turn on when the Motion Sensor finds movement?)
Second question- Which Motion Sensor do you think will be best for my goal?


GE sells a motion sensing switch (model 26931) and dimmer (model 26933)…Check them out on Amazon. The community has come up with an amazing device handler for them both that is extremely customizable.

The first question you have to answer is what do you want to control? I know you want to control a light, but are you trying to control a smart bulb in a lamp that is plugged into an unswitched receptacle or are you trying to control a switch that controls the power to the light you want to turn on?

Once that is settled and you have the proper bulb/switch, then you can use the Smartthings motion sensor (although there are a lot of others as well) placed in the stairwell.

Once you have those two pieces, the SmartLighting app (in the Classic ST app) will do what you want.

The app I use is the stock smart lighting app. It runs locally. I specifically use that for most of my motion lights. Pick a light, pick what triggers it and then set up options. For instance, my bedroom lights turn on if someone enters them but only if the luminescence is below 10lux and only up until I go to bed. They also shut off the lights after 5 minutes of leaving the room.

My bathroom lights dim to 50% from 6AM to 10AM if the luminescence is below 10lux for getting ready for work. 20% from 10AM until 10PM, 1% from 10PM until 6AM to keep from blinding me if I get up in the middle of the night. I had to do that with scenes.

You can pretty much use any compatible sensor and bulb but if you want to get lux conditions, you have to have a sensor. I use those Aeotec Z-Wave Multisensors. They do motion, temp, lux, tamper, UV, and humidity. You see where I use the lux and motion. I have one in the bathroom that also automatically controls the vent fan based on humidity.

What country are you in?

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Thanks for all the replies!
I think I understand how it all works now.
I’ll go with a smart bulb and a simple motion sensor for now and later on i’ll add a multi sensor to control the percentage of light I want :slight_smile:
Thanks again it really helped me!

@kahilzinger can you explain how you uses Scenes to set the brightness based on the Lux and time of day? I have ordered a few of the Aeotec multisensors and would like to do this but can’t see any options in Scenes to do it?

I have three scenes set up. Bathroom lights at 1%, Bathroom lights at 20%, Bathroom lights at 50%

Then in the smart lighting app, I just call that scene instead of the individual bulbs/lights/dimmers/etc.

I did find a huge error on my part. You cannot use the turn off after XX minutes because ST does not turn off scenes. Trying to figure that out.

create a separate smart lighting rule for turning off with either a new scene with off commands or the devices individually


Agreed. I just found that option. You can turn on a scene that turns off things and set it XX minutes after motion stops, though the app shows it as a beta function as far as turning off when motion stops and therefore does not run locally.

Back to my bathroom scenario, since it is one switch, I did redo that because there is an option to turn on AND set level. So, I did not have to build a scene for the bathroom lights. I just created those three rules at various dimming levels.

yeah, if its one switch or many switches at the same dim %, then you don’t need a scene.

For my kitchen, it is a little different and I created a scene to do lights at several levels and when motion stops, another scene to shut off most and bring one down to 30% dim. It only works between 30 minutes before sunset to if motion is in the room and lux is less than or equal to 10 and I am in “home” or “entertaining” (I added a custom) mode. The shut down happens between 30 minutes before sunset 10 minutes after motion stops in those same “home” and “entertaining” modes.

That way, if someone goes to the kitchen for a glass of water or something when on “night” mode, they do not get blinded. And, if it is bright enough in the kitchen, there is no need to turn on the lights during the day. If it is in “away” mode, well you just tripped my motion sensor and SMH is armed so you have bigger problems.

Welcome! :sunglasses: You might find the following two FAQs helpful. (The topic title is a clickable link. )