OpenHAB keeps last read value. Not going to NULL

1

Hi All,

I’ve got a problem where I measure temperature, and humidity from Sonoff Dual R2, with an AM2301 connected to it.

It reads the values correctly, but when I remove power from Sonoff, OpenHAB retains the last recorder value, and doesn’t show NULL…?

I’m missing something somewhere.

Below is the things file & item config.
Please assist.

Tasmota11.things

        Channels:
                Type switch : power "Power Switch 11" [
                        commandTopic="cmnd/Tasmota11/POWER",
                        stateTopic="stat/Tasmota11/POWER",
                        on="ON",
                        off="OFF"
                ]
                Type switch : reachable "Reachable" [
                        stateTopic = "tele/Tasmota11/LWT",
                        on="Online",
                        off="Offline"
                ]
                Type number : temperature "Temperature" [
                        stateTopic="tele/Tasmota11/SENSOR",
                        transformationPattern="JSONPATH:$.AM2301.Temperature"
                ]
                Type number : humidity "Humidity" [
                        stateTopic="tele/Tasmota11/SENSOR",
                        transformationPattern="JSONPATH:$.AM2301.Humidity"
                ]
}

Items was created in UI.

    "class": "org.openhab.core.items.ManagedItemProvider$PersistedItem",
    "value": {
      "groupNames": [],
      "itemType": "Switch",
      "tags": [
        "Point"
      ],
      "label": "Reachable",
      "category": ""
    }
  },
  "Powerswitch1921680111_Temperature": {
    "class": "org.openhab.core.items.ManagedItemProvider$PersistedItem",
    "value": {
      "groupNames": [],
      "itemType": "Number:Temperature",
      "tags": [
        "Measurement",
        "Temperature"
      ],
      "label": "Temperature",
      "category": ""
    }

Thanks!!

2

That’s expected behavior and working as designed. OH is event based: if you’re device is going offline than no new event is coming in. The current item state will not change automatically without a new event from the device or a rule triggering an update.

If you want your item state to become null after certain time, you need to create a rule for this.

Btw: if you post thing / item definition, please use the code tags
3

A rule is not required, use expire instead.

2 Likes
4

Hi All.
Thanks for the feedback!
I’ll give the expire a go, and revert back.

Also, just some general help…
How do I “if you post thing / item definition, please use the code tags” ??

5
6

Thanks Rich!

7

Hi All,

Just want to confirm that the expire parameter works 100% as suggested by pacive above.

Seeing as my item is not textually defined, I was able to add expiration timer in the UI under add metadata tab in Items.

Thank you for the help!!

8

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