Virtual solar sensor

Setup, Configuration and Use Scripts & Rules
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10

I have been able to make this much simpler by using the new Synop Analyzer binding and the Radiation channel in the Weatherunderground 2.0 binding. This is the net result of it:

/*
* Rules to calculate outside light lux.
* Basic idea from Domoticz LUA script at https://www.domoticz.com/wiki/Real-time_solar_data_without_any_hardware_sensor_:_azimuth,_Altitude,_Lux_sensor...
* Authors: Sébastien Joly, Neutrino, Jmleglise
*
* Adapted to openHab rule by mherwege
* 23-Jun-2017	Modified to use Okta from Synop Analyzer binding and Radiation from Astro binding
*				These bindings already do most of the queries and calculations
*/

/*
* Required openHab items as input:
* 	Number Okta					current okta value from Synop Analyzer binding
*	Number TotalRadiation		current total solar radiation from Astro binding
* 
* Required openHab items storing results:
* 	Number Lux					radiation in Lux
* 	Number WeightedLux			radiation in Lux corrected for cloud layer
*/
 
rule "Calculate outside light"
when
	Item Okta changed or
	Item TotalRadiation changed
then
	// Okta
	var int vOkta = (Okta.state as Number).intValue
	var double vTotalRadiation = (TotalRadiation.state as Number).doubleValue

	// Factor of mitigation for the cloud layer
	var double Kc = 1 - 0.75 * Math.pow(vOkta/8.0, 3.4)
	
	logInfo("Light", "Kc {}", Kc)

	var double vLux = vTotalRadiation / 0.0079	// Radiation in Lux. 1 Lux = 0.0079 W/m²
	var double vWeightedLux = vLux * Kc			// radiation of the Sun with the cloud layer

	Lux.postUpdate(vLux)
	WeightedLux.postUpdate(vWeightedLux)
	
	logInfo("Light", "Lux {}", vLux)
	logInfo("Light", "WeightedLux {}", vWeightedLux)
end
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