Change the precision of temperature sensor

BennRick · August 15, 2023, 3:42am

I’m trying to get HA to report temperature to 1 decimal place (e.g. 17.6).

My aeotec Multisensor 6 sensors feed HA via ZWave, a Hubitat Hub and MQTT
The hub reports temps to 1 decimal place
MQTT Explorer shows the temps it is passing to HA to 1 decimal place
I’ve used Display Precision to set the temp sensor entities to 1 decimal place
The dashboard displays temps to 1 decimal place, but always ending with ‘.0’
History displays charts where the temp changes by whole degrees
DevTools States shows the temperatures as whole numbers
I have other temperature sensors that HA does report to 1 decimal place

I figure I’m missing something obvious here. Can anyone give me a clue?

koying · August 15, 2023, 8:38am

How is the sensor defined in HA?
In a MQTT sensor in configuration.yaml? Then show it.

BennRick · August 17, 2023, 1:59am

The sensor is defined to HA through the Hubitat integration. It is not referenced in configuration.yaml
Here is what MQTT is passing (from MQTT Explorer).

Here is what HA is reporting.

Seems to me that HA is picking up the temperature to 1 decimal place, but storing and reporting it using whole numbers.

koying · August 17, 2023, 6:36am

Through the custom integration in HACS? There is no builtin one. Did you ask the dev about this peculiarity?

And then, how is MQTT relevant? That integration is using Hubitat API, not MQTT

BennRick · August 17, 2023, 6:55am

Yes. Through the custom integration in HACS.

I think the Hubitat custom integration uses MQTT to transmit messages between the Hubitat Hub and HA. I can’t think of any other way to explain the sensor showing up in MQTT Explorer (in the Homie group - source of the graph already shared) or MQTT being mentioned on the HA device screen for the sensor, as shown here:

koying · August 17, 2023, 7:13am

Well, no. Your screenshot shows it goes indeed through MQTT, not through a HA Hubitat integration.
As you seem unaware, you surely didn’t define the MQTT sensor manually in HA, so it comes from a discovery topic.

That topic is likely named homeassistant(ha_stream for me)/sensor/<name_of_sensor>/config
Please post its content.

BennRick · August 17, 2023, 7:27am

I believe the sensor in HA was set up by the Hubitat integration. As you say, I didn’t do it manually.

Is this what you are looking for?

koying · August 17, 2023, 8:02am

See above

BennRick · August 17, 2023, 12:04pm

Aaah. I see it now. Thank you. But how can / where do I change it?

petro · August 17, 2023, 12:18pm

That’s done in whatever’s creating that discovery information. I.e. the custom integration.

Your other option is to just manually add the entity yourself using MQTT yaml.

koying · August 17, 2023, 12:35pm

I don’t think there is a custom integration, at least not an HA one (what would be the point to go through MQTT?).
There is some confusion, here, and I suspect it is some sort of Hubitat addon.

petro · August 17, 2023, 12:37pm

Yes, whatever it is (addon, integration), it’s creating the rounded discovery information. Once OP figures out what’s creating that discovery, he can move on to fix it.

BennRick · August 17, 2023, 10:01pm

Thanks for your help guys. I will leave this open for now. Will investigate further and post an update once I have figured out how to change the precision.

I’m thinking it has to be something on the HA side of the MQTT Broker , since MQTT Explorer shows the broker is getting the temperature to one decimal place. Whatever it is was probably put there by the HACS Hubitat custom integration.

petro · August 17, 2023, 10:34pm

My man, it’s the discovery info being sent to HA. It’s not where you think it is. You already proved this by showing us the discovery info. You’re welcome to ignore the advice, but realize that you’re chasing something that’s not the problem.

francisp · August 18, 2023, 3:53am

Copy the discovery information using MQTT explorer, create a script that republishes is without the
| round(0)

koying · August 18, 2023, 6:47am

OP, you installed a MQTT app on your hubitat hub, likely that one:

The error comes from there

github.com

Gledholt/TTQM5/blob/9bd35e26a96072528406454530672bb06fcb13dd/MQTT app#L2929

    
      
                          else pDevClass = ',"device_class": "notHandled"'
          				//else if (category == "battery") pDevClass = ',"device_class": "battery"'  // LOW/OK indicator, perhaps set if < 10%
          				//pON = ',"payload_on":"'+payON+'"'  //TODO check if this is ever needed for boolean sensors - will be for enum
          				//pOFF = ',"payload_off":"'+payOFF+'"'   //TODO need a selector here
          				pUOM=''
          			}
          			if (type=="sensor") {
          				pUOM=',"unit_of_measurement": "'+UOM+'"'
          				pON=''  // remove on:off states from sensor adverts ? Do I need to be more selective say with some (analogue?) 'sensors' that might also have an on:off state ? TODO check
          				pOFF=''
                          pValTemp = ',"value_template":"{{ value | round(0) }}"'  // acts as convert to int
          				if (category == "measure-temperature")  { 
          				    pDevClass = ',"device_class": "temperature"'
          				    if (tempUnits=="Celsius x.x°C")	pValTemp = ',"value_template":"{{ value | round(1) }}"'
                              else if (tempUnits=="Fahrenheit x.x°F")	pValTemp = ',"value_template":"{{ value | round(1) }}"'
          				}
                          else if (category == "measure-battery") pDevClass = ',"device_class": "battery"'
                          else if (category == "illuminance") pDevClass = ',"device_class": "illuminance"'
                          else if (category == "signal_strength") pDevClass = ',"device_class": "signal_strength"'
                          else if (category == "humidity") pDevClass = ',"device_class": "humidity"'
                          else if (category == "power") pDevClass = ',"device_class": "power"'

It seems you might fix it by setting your tempUnits to Celsius x.x°C in the config.

BennRick · August 20, 2023, 3:44am

You were right! It’s been so long since I set these sensors up that I’d forgotten how they were working. Thank-you for your pointing me in the right direction. For the benefit of anyone else reading this, here’s what you need to do (using the Hubitat Hub app)

Step 1: Open the MQTT app

Step 2: Click on Configuration

Step 3: Click on the Temperature Units drop down and select the option shown in the picture below

That’s all there is to it! The change should have immediate effect.

koying · August 20, 2023, 7:27am

Glad that it is solved, but for the future, try to understand and take note of how your setup works.
You were lucky that I like detective work, here