Luminance settings for lights

Hi all,

I’ve got a couple of Phillips Hue sensors that have illuminance settings and I’d like to write some rules that, on sensing movement, determine whether to turn the light on or not.

I’ve got the rule down already but it is currently running on a combination of time of day and astro dusk settings but Ifind it wanting a bit this time of year as the light varies greatly depending on weather / cloud cover etc so can be a bit hit or miss.

I wanted to run it by the actual illuminance in the room from the sensor.

Does anyone have some real life illuninance levels that they work by for needing lights on / off???

I use individual illuminance sensors throughout the house along with…

I don’t recall if I’ve pushed those changes, but I am about to push a large update.

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I use time of day rules so I can have different light level for when I get up in the middle of the night and don’t need blasting lights. It comes in handy now I am officially old

I also use time of day type rules and astro rules to control light levels but I also use a luminance sensor to control my lights. I have a Hue motion sensor that I used for this purpose that is pointed directly out a window to sense outside light levels. I found the Hue sensors to be lacking a little about reporting motion and eventually moved on to using zwave sensors for my motion detection but repurposed the Hue sensor for luminance. My system is set up so during the day as the outside light level varies, the inside lights adjust up and down to compensate for the level of natural light.
This is actually one of my favorite features of my home automation system. Eventually however, I got sick of the batteries dying in the Hue sensor. Since the system relied on the Hue sensor, when the batteries went flat, the system ceased to function correctly. I wanted a sensor that was mains powered and didn’t need batteries but didn’t find to many that didn’t include a bunch of other functionality that was useless in this scenario. I ended up making my own using an esp8266.
The Hue reported light level every 5 minutes. I think the reporting interval is adjustable but making it report more often just made it kill the battery quicker. Because the esp8266 is mains powered, I can have it set to report every thirty seconds. Now the lights in my flat adjust in real time (practically) and it is really subtle but super cool. If the sun goes behind a cloud, the light come up, when the sun pops back out the lights go back down, I love it!

Thanks all, I’ve got a hue sensor too. I use the time of day rules and Astro at the moment I report on the the ‘dusk’ setting but as it’s an arbitrary time I find that this time of year a cloudy day means we need lights on before the setting kicks in.

So what luminance / lux numbers do you all use as your ‘threshold’ for turning the lights on?

That’s pretty awesome. How do you setup which should get priority between brightness or time of day?

Wonder if I could use the solar generation figures from my roof to determine lux levels…

@MadFrankie I believe it depends too much based on environment to go off someone else’s lux numbers. There are so many variables (amount of natural light available your particular environment, season, volume/placement of your interior lights) involved which can affect the effectiveness of your strategy.

For instance, some areas of my house have mostly shade covered windows while some have directly south facing windows or skylights. I had to go off logging the brightness and trial and error to find a reasonable lux level for our house.

Good point, was just trying to jump ahead and save me some logging time but you’re right, I’ll get some logging on the lux readings over the next few days and go from there. :+1:

The time of day thing is more like do this other stuff when it isn’t daylight hours. Sort of…
In other words, at night (after dark) do this. But really late at night, (after bed time) do this. And at the very early morning, do this other thing. But then, during the part of the day where it is daylight, usually, and the windows and doors are providing natural ambient light, then let the sensor control stuff

probably… That would tell you how much over all sunlight for sure :+1:
I can’t do that because I’m in a 3rd floor flat with windows to outside only on one wall so I point the sensor straight out the kitchen window :blush:

The Hue motion sensor reports light level in lux. I tried a few different sensors with my esp8266, for instance the adafruit tsl2561 which is a digital sensor which reports in lux also. And several others.
They all agree when it’s dark :rofl:
But roughly…
If it is over 10,000 there is no need for lights to be burning electricity (ya might even wanna close the blinds a little) under 1000, it’s almost dark, you need lights on to see. in between is… well up to you.
I use the first two digits to set my dimmers since openhab dimmers are 0 to 100
Anything > 9999 no lights
Anything <100 full light by other means of setting level
anything in between - invert first two digits
lux 7500 = dimmer setting 25
lux 2500 = dimmer setting 75
adjust for personal preferences