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I am looking for an outdoor light sensor that is compatible with the RFXCOM USB RFXtrx433 transceiver (I use it in combination with a Vera Lite Home Controller).

I know there are KaKu Dawn sensors but I hear that KaKu sensors are not that great and I want a sensor that gives a value (light intensity) rather than a sensor that just says it's dark or light outside.

Does something like that exists?

Z-wave based would be better but I can't find that many outdoor Z-wave sensors and they are usually a lot more expensive.

I have 2 backup solutions if this product doesn't exist:

- Using a RFXSensor with a simple photocell (also rather expensive)
- Building something from scratch with an Arduino/JeeNode (would love to talk to the RFXCom transceiver but I don't know which protocol to use)

the MS13 can be used. It has a light/dark sensor.

That's not what I want because that works just like a dawn sensor. I want a light intensity sensor: it should return a numerical value and not a Boolean (on/off).

I want to use it for example to determine at what dim level the lights should be switched on when motion is detected. I could use the current time but using (outdoor) light intensity seems more logical/cooler .

Another solution might be to check how long ago an outdoor MS13 detected that it became dark/light and guess how dark it is at that moment. To calibrate the value I could use the length of the previous night(s).

Just brainstorming .

The kaku sensor has adjustable levels IIRC.
And have you considered using a LDR.

Digit wrote:The kaku sensor has adjustable levels IIRC.
And have you considered using a LDR.

Yes but it still works as a night/day sensor, not as a sensor that gives a light intensity value.

I have considered using a LDR but then I would have to create a sensor myself (and make it weatherproof). I prefer a standard solution, but if that doesn't exists I seriously have to consider creating something myself.

I hope I can find some information on how to create a RFXCom compatible sensor with a JeeNode for example.

Maye the uk.oregonscientific.com/cat-Price-sub-% ... AR908.html Oregon UV sensor is what you want?

You can also just use a camera for that.. see

http://www.bwired.nl/weblog.asp?id=435 and
http://www.binkey.nl/2011/12/04/mobotix ... -homeseer/

You get a nice camera and a good light sensor, but a bit pricey. But for all we know, you could have one hanging around.

I use that one too (camera sensor); it's the best I've seen so far; here's a Lux sensor compared to the Mobotix camera sensor. The last one is much better - less influenced by cloudy weather and a very stable signal, especially during sunrise and sunset.

Interesting approach. I am planning to buy some addition webcams (an outdoor one as well). I could analyze the webcam image on light intensity and create my own virtual device plugin for Vera.

I only thought of the hardware approach. I find that quite funny because I am a developer .

My camera has the lux sensor build in, so no need to analyze the pictures and such.

I don't recommend an Oregon UVR128 for any purpose!
I own one for many years, it eats batteries like an electric heater and during the last 3 years it never reported anything else than uv level 1-2, it's sitting in the middle of my garden with cleaned lens and everything.

A bit of topic (since not supported by Vera and it's a DIY project) is this one:

http://lika.be/wp/2009/06/self-powered- ... ht-sensor/
I find this a very cool one -like the rest of the modules on this site- which is on my to-build list for some time.
It sends its data on 433Mhz, in a custom protocol picked up by a wireless gateway, so you have to build this too, (see also the googlecode link, and same site for more info) maybe the protocol can be tweaked to mimic a device supported by RFXtrx.