So on my setup (3.2.0 on RPi) I’ve got Mosquitto setup and running nicely and I can see in it’s logs that Openhab is connecting just fine. I can verify that my several ESP8266’s are sending data and I can confirm it with testing via the command line mosquitto_sub tool from a remote system. So data is definitely flowing into the system. For reference i am using the PubSubClient and the publish code looks like this:
// Publishes Temperature and Humidity values
static char temperatureTemp[6];
dtostrf(f, 6, 1, temperatureTemp);
static char humidityTemp[6];
dtostrf(h, 6, 1, humidityTemp);
client.publish("sensors/frontroom/temperature", temperatureTemp);
client.publish("sensors/frontroom/humidity", humidityTemp);
The problem I’m having is how to get that out into my sitemap. I started by following the tutorial and I created the MQTT Broker. Then I created a Generic MQTT Thing based on the broker:
Then in the generic MQTT Think I created a channel for the topic:
and lastly I created the point item that is linked to that channel.
So I have two issues. When I try to load the sitemap with the data:
Text item=FrontroomTemp label="Frontroom [%.1f °F]"
the mobil app just says “Err” and the logfiles show:
2022-03-31 20:19:12.658 [WARN ] [ui.internal.items.ItemUIRegistryImpl] - Exception while formatting value '' of item FrontroomTemp with format '%.1f °F': f != java.lang.String
I’m not exactly sure what I am doing wrong here. For some reason it seems to be getting a null or zero length string from the topic.


