Measuring Lux inside or outside?

  • Platform information:
    • Hardware: RPi 3
    • OS: OpenHabian
    • Java Runtime Environment: Zulu
    • openHAB version: 2.5M1
  • Issue of the topic:
    For my rollershutters I want to measure if there is much sunlight (e.q. not cloudy). The method I use now is by the OpenWeather binding (cloudiness), but I want a more accurate solution.
    So I was thinking of measuring the lux by a lux sensor (Zwave: Fibaro Motion or Aeotec Tri/multi sensor). The only doubt I have is whether I place the sensor inside (the room) or outside.
    Does anyone have any suggestion?

The miflora will be the cheapest sensor for this

Difficult, same problem here. Both sensor enclosures aren’t waterproof. But if you wrap them into another enclosure it’ll do, then putting them outside gives better accuracy.
Also remember to use a sliding window to get an average across multiple measurements.

I have a Hue motion sensor, which has a light sensor, pointed out a window. I use the Hue because it responds in near real-time. Sun goes behind a cloud, lights get brighter, sun comes back out, lights dim.

I think I’ve the answer to my own question :laughing:
For the use with rollershutters, it needs to be outside. Otherwise the sensor can’t measure the lux if the rollershutter is closed :upside_down_face:
The Aeotec Multi and Tri sensor are IP20, but according to the manual, if it is under a roof or protected against rain, you can use it outside.
A dutch webshop created an outdoor wallmount for the fibaro motion sensor or Neo Coolcam motion sensor link (NL) link (EN)

Careful, I’ve trashed more than one of them by using them outside. I’ve now put them into another IP6x enclosure.

I have a Hue motion sensor (which also reports luminance) pointed out a window!

(and birdies flying by my 3rd floor flat window)