Measuring Lux inside or outside?

Setup, Configuration and Use Runtime
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  • 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?
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The miflora will be the cheapest sensor for this

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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.

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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.

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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)

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

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

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