Wrong readings in Knob widged vs Dummy widget

Tags: #<Tag:0x00007f61739ab718>

Hi to everibody!

II have openhub 2.5.2 running from years on a Qnap NAS controlling a Bticino Myhome’s sensors/switchs/roller shutters/ecc plus other cards to support a deep home automation integration.

Because i need to add few temperature sensors, i was testing the LAN DS18B20 WEB Temperature Monitor card from KMtronic which gives all sensors status using a XML file using the following .items:

String Sensor1 “Temperatura [%s]” { http="<[http://88.87.29.196:8002/status.xml:5000:XPATH(/response/sensor/temp/text())]" }
String Sensor2 “Temperatura [%s]” { http="<[http://88.87.29.196:8002/status.xml:5000:XPATH(/response/sensor[2]/temp/text())]" }
String Sensor3 “Temperatura [%s]” { http="<[http://88.87.29.196:8002/status.xml:5000:XPATH(/response/sensor[3]/temp/text())]" }
String Sensor4 “Temperatura [%s]” { http="<[http://88.87.29.196:8002/status.xml:5000:XPATH(/response/sensor[4]/temp/text())]" }

The items as the XPath Transformation works perfect and i have my temperature values as you can see from this picture where in the first row i used Knob widget, in the second Dummy widget.

As you can see as soon i download the webpage in the knob widget i have the right value but after the automatic refresh, the value change and it seems that is rounded to the closest 1 degree value.
The dummy widget always showing the right value.

Any idea on whats happening??

No errors on log file…

Thanks for any tips.

All I can say is, I have the same problem. I have temperature readings from a few DS18B20 probes controlled by an Arduino sketch on a D1 Mini, and sent to openHAB over MQTT. The values are correct everywhere, except on my knobs in HABpanel. PaperUI is fine (matches the values in the logs).

But right now my measurements are 82.6 F, 81.7 F and 25.4 C, but in HABpanel they show as 80.0 F, 80.0 F and 25.0 C respectively. As you said, it seems like the values get rounded to some degree, but it’s not clear why and how.

If I refresh the page, the correct values will be shown initially, but revert to some rounded values after a while. They don’t revert all at once – one will switch after a few seconds say, then another later… Within about a minute they will all be wrong. Maybe they only revert when the value changes from the original? Limited observation seems to agree with that theory.