I just got myself a couple of Aqara motion sensors that supports illumination reading.
I was hoping I could use it to detect the outdoor Illumination in order to automate the lighting in the house.
Unfortunately, it seems the illumination value doesn’t change until motion is detected. The illumination value is tied with the motion value.
Is anyone else facing this problem? Do you have any workaround for this?
I have the body motion sensor that supports lux. Updates on regular basis without motion.
I have the two generations of the motion detection. First one hasn’t illumination value and I’m quite happy with it.
Second generation makes me regret the first one, the only add-on is the illumination sensor, and it’s not usable. Will only react to direct light, not the room illumination (while the Xiaomi gateway illumination sensor is much more reliable), won’t update regularly, most of the times it updates when direct lightning changes a lot (but not always).
Is this the one you are getting?
As you can see, the value hasn’t been updated for more than one hour…
I put it at outdoor and it was pretty accurate as long as there are motion detected. At night with lights, the value is around 20 lx (as per my screenshot). Without lights, the value drop to 3 lx. I have 2 units and both result were pretty consistent.
If yours with lights on is around 6 lx only, maybe the illumination sensor is not working properly.
After using this for a day, I notice the lux value does change by itself without detecting any motion. But the frequency is not consistent and not fast.
Right now, it is raining and the sky is dark. The lux value drop from 1000 (max) to 136.
I guess it works as expected. Will monitor for few more days and share the findings here.
Actually, it seems to be a documented behavior for this type of Xiaomi sensors. They update illumination value at the same moment as motion is detected. Otherwise they send updates to Xiaomi gateway about once per hour (55 minutes in my case) with the current illumination value.
I believe this is to preserve the battery.
i see. i’m wondering is it possible to change the update frequency of the illumination value?
It works, I tried and put it outside to check. That’s why I told you it only reacts to direct light, not room’s illumination.
I have only 6 lux here, it’s a corridor without windows but when doors are open, the sunlight doesn’t change it much. Neither does the LED light there is in it. Only and old halogen light works.
It looks like there are some cases when it updates the luminosity even if there is no motion detected. Big change in the value ?
my car porch has only 3 LED bulbs. When it’s on, the lux jump to around 20 something lx. When it’s off, it went down to 2 to 3 lx only. Maybe you can move your sensor nearer to the LED light?
The place I’ve put it, on the ceiling, is where it can detect motion in the corridor but also in the stairs, as far as possible. It was my main concern : detect motion, so that I can turn the light on when someone is climbing the stairs.
I expected more, only turn it on when there is no other light or the daylight through a door is enough. But between 0 and 10 lux, 4 to 6 most of the time, the range is too small to make any sense. So I use the time of the day and the sun elevation !
I’ll be buying other motion detector from Xiaomi, I’ll try to get the first generation on sale if I can, anyway I won’t expect to use illumination sensor if I end up with a second generation !
I do not think it’s possible. There has been a lot of discussion on update frequency of the temperature/humidity sensors as well.
