[SOLVED] NAN when linking Item to Generic MQTT Thing

Setup, Configuration and Use Items & Sitemaps
1

Hi I am a bloody beginner with openhab and hope that my silly question does not bother you too much.

I am using Openhab 2.4 on a Raspberry Pi.
A ESP8266 is sending temperature values to the mosquitto broker embedded on the Pi (Channel /esp8266_station123/out)

I have connected the 2.4 Mqtt Binding to the mosquitto server and it is online according to the paperui.

Under the generic MQTT Thing i linked the thing to the broker and generated a new channel. I linked the state topic of the channel to the ā€œesp8266_station123/outā€ Channel.

Finally i linked this new Channel to a new Item.

Now, when i click in the control tab, i can see the new item. But its value is NAN

I checkt the esp8266_station123/out-Channel via MQTT.fx and i can see that the Esp is sending numbers, so here everything is fine and i quess it is a wrong setting in the PaperUI.

I wasted(?) my complete evening on this topic, and couldnā€™t find a solution. Maybe you guys can help me.

Desperate Regards,
Arne

2

I donā€™t think Iā€™ve seen a NAN or NaN. Not that I use control tab much, but feels like a clue. An invalid Item state would normally come up NULL or UNDEF. Formatting issue?

May we see your Item definition?
What does events.log tell you about that Item?
Any clues in openhab.log?

3

What firmware are you using with the esp device?

4

Hiā€¦ here is the Openhab log , the one from http://openhabianpi:9001 (events.log?) relevant for mqtt things after start up:

Blockquote

2019-02-10 08:39:04.400 [.ItemChannelLinkAddedEvent] - Link ā€˜GenericMQTTThing_Temperature-mqtt:topic:48450fd7:temperatureā€™ has been added.

2019-02-10 08:39:04.410 [.ItemChannelLinkAddedEvent] - Link ā€˜ESP_Temperature-mqtt:topic:48450fd7:testā€™ has been added.

2019-02-10 08:39:04.969 [hingStatusInfoChangedEvent] - ā€˜mqtt:topic:48450fd7ā€™ changed from UNINITIALIZED to UNINITIALIZED (BRIDGE_UNINITIALIZED)

==> /var/log/openhab2/openhab.log <==

2019-02-10 08:39:06.294 [INFO ] [.dashboard.internal.DashboardService] - Started Dashboard at http://192.168.0.132:8080

2019-02-10 08:39:06.299 [INFO ] [.dashboard.internal.DashboardService] - Started Dashboard at https://192.168.0.132:8443

2019-02-10 08:39:07.112 [INFO ] [arthome.ui.paper.internal.PaperUIApp] - Started Paper UI at /paperui

==> /var/log/openhab2/events.log <==

2019-02-10 08:39:07.656 [hingStatusInfoChangedEvent] - ā€˜mqtt:broker:1ce33688ā€™ changed from UNINITIALIZED to INITIALIZING

2019-02-10 08:39:07.987 [hingStatusInfoChangedEvent] - ā€˜mqtt:broker:1ce33688ā€™ changed from INITIALIZING to OFFLINE

2019-02-10 08:39:08.076 [hingStatusInfoChangedEvent] - ā€˜mqtt:topic:48450fd7ā€™ changed from UNINITIALIZED (BRIDGE_UNINITIALIZED) to INITIALIZING

2019-02-10 08:39:08.175 [hingStatusInfoChangedEvent] - ā€˜mqtt:topic:48450fd7ā€™ changed from INITIALIZING to OFFLINE (BRIDGE_OFFLINE)

==> /var/log/openhab2/openhab.log <==

2019-02-10 08:39:08.215 [INFO ] [.transport.mqtt.MqttBrokerConnection] - Starting MQTT broker connection to ā€˜localhostā€™ with clientid paho69695361643 and file store ā€˜/var/lib/openhab2/mqtt/localhostā€™

==> /var/log/openhab2/events.log <==

2019-02-10 08:39:08.378 [hingStatusInfoChangedEvent] - ā€˜mqtt:broker:1ce33688ā€™ changed from OFFLINE to ONLINE

2019-02-10 08:39:08.419 [me.event.ThingUpdatedEvent] - Thing ā€˜mqtt:broker:1ce33688ā€™ has been updated.

2019-02-10 08:39:08.437 [hingStatusInfoChangedEvent] - ā€˜mqtt:topic:48450fd7ā€™ changed from OFFLINE (BRIDGE_OFFLINE) to ONLINE

Blockquote

In the openhab.log there is just this line mentioned:

2019-02-10 08:39:08.215 [INFO ] [.transport.mqtt.MqttBrokerConnection] - Starting MQTT broker connection to ā€˜localhostā€™ with clientid paho69695361643 and file store ā€˜/var/lib/openhab2/mqtt/localhostā€™

The Esp is a ESP12 using the following moduls:
NodeMCU custom build by frightanic.com
modules: dht,file,gpio,mqtt,net,node,tmr,uart,wifi

Where can i find the config file of the generic mqtt thing?
Here are two screenshots.
https://imgur.com/a/1j4ASBF
Do i need to make a transformation of the MQTT Value?

5

That depends, what is the mqtt payload? EXACTLY?

Your state topic is wrong:

There is a leading /

Your state topic in your MQTT thing is esp8266_station123/out without the leading /

So your either remove the leading / from the ESP code (BEST PRACTICE). Leading / are not recommended even though it still works because they lead to errors (Just like yoursā€¦)
Or you add a leading / to your state topic in your MQTT thing

1 Like
6

THANK YOU very much, it was the leading / in the esp codeā€¦

I am so glad that you found my error (or to say, the error from the tutorial which i used).

Thank you, thank you!

7

You are welcome,
Please like and tick the solution mark on the post. Thanks