How to use distanceFrom on Raspberry Pi (Openhabian)

[PyroEngineering (Thomas Eschenmoser)]

I had a rule using distanceFrom on my Synology NAS installation that worked just fine.

Items:
Location Home_L0800
Number Home_N0803
Location iPhone6S_Location

Rule:
rule “Distance”

when
Item iPhone6S_Location changed
then
Home_L0800.state = new PointType(new DecimalType(00.000000), new DecimalType(00.000000))
Home_N0803.postUpdate(Home_L0800.distanceFrom(iPhone6S_Location))
end

Since Openhab is no longer supported on Synology NAS I am now running openhab on a raspberry pi.
I can’t figure out how to use distanceFrom in a rule on the raspberry pi.

Can anyone give me an example please?

[rossko57]

@PyroEngineering

(iPhone6S_Location)

You’d usually be interested in the state of an Item

@PyroEngineering

Home_L0800.state =

While that might work, it is recommended to use postUpdate
Home_L0800.postUpdate(whatever)
That should be a reminder that this Item is not a simple variable, and results take time.
Don’t expect to use the new state in the next line, it will not have happened yet.
You might want to look at this

Http call not sent to all end points (Set room temperature)

The example with logging added itemX.postUpdate(some-value) logInfo("test", "State was "+ itemX.state) // this will report the OLD value, the update has not happened yet. // // but - we already know what we sent it logInfo("test", "State will become " + some-value) It is very rare that you need to code any “wait” for this; just think clearly about what you need and choose rule triggers carefully. Items are not simple variables.

[PyroEngineering (Thomas Eschenmoser)]

Thank you very much for your answer. In the meantime I tried various things.
The line

Home_N0803.sendCommand(5)

as well as

Home_N0803.postUpdate(5)

work just fine.

What seems to be the Problem is the

Home_L0800.distanceFrom(iPhone6S_Location)

part.

Means the Line

Home_N0803.postUpdate(Home_L0800.distanceFrom(iPhone6S_Location))

has no impact on the state of Home_N0803.

Is there something wrong with my code?

By the way: is there something like a log file which shows errors in scripts/rules on the raspberry pi? This was very helpful to me while I was running OH on the NAS.

[rossko57]

@PyroEngineering

By the way: is there something like a log file which shows errors in scripts/rules on the raspberry pi?

Yes, it’s essential that you find that. It’ll be openhab.log just as it was on the NAS, but the folder structure is a bit different.

@PyroEngineering

Home_L0800.distanceFrom(…

You can’t get the distance from an Item. A general Item might represent a phone number or temperature. It just doesn’t have a distanceFrom() method.

Items do have state, though.
Some Items may have a state that represents a location or point.
You can get distance from that - the state, not the whole Item.

And of course you would need to compare with another point, not a whole Item.

Group wise distance calculation for variable locations in a group (.distancefrom on String)

I finally found a working solution: val PointType loc = triggeringItem.state as PointType // for .distanceFrom either both need to be PointType or Location - I guess and don't know, what's the difference between them. val PointType home = Loc_Home.state as PointType val String whoDH = who + "_Dist" // distance (item name) from home for who val whoDHitem = ScriptServiceUtil.getItemRegistry.getItem(whoDH) // distance (real item itself) from home for who // who's distance from home val distH = (lo…