Aqara Sensors: Combining Lux and Motion for Smart Lighting

Aqara Products
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Hey everyone, just wanted to share a little win from the past week that seriously boosted the vibe at home.

I’ve been playing around with the Aqara Motion Sensor P1 and a Light Sensor (got the T1 model), trying to fine-tune my lighting setup. Basically, I wanted lights to turn on only when someone walks in AND it’s actually dark — not just every time the cat walks by during daylight.

After a bit of fiddling and a YouTube rabbit hole or two, I finally managed to nail it using both sensors together via Home Assistant. When lux levels drop under, say, 20lx AND motion is detected, boom, hallway lights on. If it’s brighter, nothing triggers, even if there’s motion. It sounds simple, but the effect is slick.

Also added a delay and condition to not retrigger constantly — saved me from that disco hallway look (you know what I mean).

Anyone else using lux + motion logic? Would love to hear your setups or tweaks. Especially curious if anyone’s found a good lux threshold that works consistently across seasons. My living room window light changes like crazy.

Let’s swap setups!

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@NestNerd Hey there! :wave:

First off, congrats on nailing that setup—it sounds super slick! Combining lux and motion is such a game-changer, especially for avoiding those “cat-triggered disco hallways” (been there, haha).

Your 20lx threshold is a solid starting point! For seasonal adjustments, you might experiment with slightly higher thresholds (e.g., 30-50lx) during winter when natural light is weaker, or tweak it based on the room’s orientation. Some folks even use adaptive thresholds tied to sunrise/sunset data in Home Assistant for consistency.

I’ve seen others layer in extra logic, like:

  • Time-based overrides: Ignoring lux during late-night hours when you always want lights on.
  • Room-specific thresholds: Kitchens often need lower lux triggers than hallways.
  • Occupancy checks: Adding door sensors to confirm someone’s actually in the room (not just passing by).

Would love to hear how your living room tweaks go—window light can be so unpredictable! Keep us posted, and happy automating! :rocket:

P.S. Your “YouTube rabbit hole” comment is too relatable. The things we do for smart home perfection… :joy: