Temperature conversion problem

Setup, Configuration and Use Scripts & Rules
1

Im trying to convert temperature readings from a 433MHz-device. I have a rule by AndrewZ as a model:

val Functions$Function1<Number, BigDecimal> convertTemp = [ tempData |
        if (tempData < 32768) { tempData/10 }
        else { (32768 - tempData)/10 }
]
rule "Temperaturkonvertering 1"
when
        Item utetemp1_raw changed
then
        var String tempHex = utetemp1_raw.state.toString
        var int tempDec = Integer::parseInt(tempHex, 16)
        utetemp1.postUpdate(convertTemp.apply(tempDec))
end

Unfortunately it doesn’t work and I get the following error:

An error occurred during the script execution: Could not invoke method: org.eclipse.smarthome.model.script.actions.BusEvent.postUpdate(org.eclipse.smarthome.core.items.Item,org.eclipse.smarthome.core.types.State) on instance: null

Help appreciated!

2

Are you certain utetemp1 exists and is exactly like written, case and everything?

The error implies that utetemp1 doesn’t exist, or the lambda is returning null.

3

Yes it does… and it is correctly spelled…

The problem seems to be the function … I moved this into the rule instead:

   if (tempData < 32768) { tempData/10 }
        else { (32768 - tempData)/10 }

And then it works without any problems…

4

Perhaps the result of the calculation isn’t a BigDecimal, even though it is supposed to be.

What if you force it, or use Number instead?

Force it

if(tempData < 32768) { tempData/10 as BigDecimal }
else { (32768 - tempData)/10 as BigDecimal }

Use Number

val Functions$Function1<Number, Number>