MQTT autodiscovery topics and measurement units in Acurite weather station

[shampeon]

I just set up as Docker containers rtl_433 along with rtl_433_autodiscovery to wrap rtl_433_mqtt_hass.py. I can see the output of the sensors in my new Acurite 5-in-1 station now in Home Assistant:

I'm not totally sure why the sensors only have suffixes (e.g. -F, -RT, etc.).

I'm in the US, and have set the units to F/in/mph on the Acurite display, and the units are set to the same in Home Assistant. But as you can see the temperature is correctly outputting Fahrenheit, but the rain total and wind speed are in metric.

Looking through my autodiscovery topic in MQTT, I see that the sensor is converting from the imperial value back to metric for e.g. rain rate:

{"name": "Acurite-5n1-B-2898-RT", "unit_of_measurement": "mm", "value_template": "{{ (float(value|float) * 25.4) | round(2) }}", "state_class": "total_increasing", "state_topic": "rtl_433/5687e923fbb8/devices/Acurite-5n1/B/2898/rain_in", "unique_id": "Acurite-5n1-B-2898-RT", "device": {"identifiers": ["Acurite-5n1-B-2898"], "name": "Acurite-5n1-B-2898", "model": "Acurite-5n1", "manufacturer": "rtl_433"}}

Note the state topic is rain_in.

I'm a little confused why this conversion is happening. Setting -C native in rtl_433 doesn't have any effect.

What I want is for the sensor data in HA to match the global unit setting in HA.

In rtl_433_mqtt_hass.py these are the mappings for the sensors for rain_mm and rain_in:

    "rain_mm": {
        "device_type": "sensor",
        "object_suffix": "RT",
        "config": {
            "device_class": "precipitation",
            "name": "Rain Total",
            "unit_of_measurement": "mm",
            "value_template": "{{ value|float|round(2) }}",
            "state_class": "total_increasing"
        }
    },
...
    "rain_in": {
        "device_type": "sensor",
        "object_suffix": "RT",
        "config": {
            "device_class": "precipitation",
            "name": "Rain Total",
            "unit_of_measurement": "mm",
            "value_template": "{{ (float(value|float) * 25.4) | round(2) }}",
            "state_class": "total_increasing"
        }
    },

Is it wrong that both rain_mm and rain_in have "unit_of_measurement": "mm"? Is that why the -RT sensor is showing in mm?

[zuckschwerdt]

That conversion snuck in with #1390 and likely should not be there. Units are selected with
[-C native | si | customary] Convert units in decoded output.

[shampeon]

So changing my rtl433 container to use -Ccustomary:

  rtl433:
    container_name: rtl433
    image: hertzg/rtl_433:latest
    devices:
      - "/dev/bus/usb/001/004"
    command:
      - "-Mtime:unix:usec:utc"
      - "-Mbits"
      - "-Mlevel"
      - "-Mprotocol"
      - "-Mstats:2:300"
      - "-Fmqtt://172.17.0.1:1883,user=xxxxxxx,pass=xxxxxxxx,retain=1"
      - "-Ccustomary"

Results in the correct units for everything except rain_in.

I'm thinking the fix is to flip the value_template for rain_in and rain_mm. E.g.:

    "rain_mm": {
        "device_type": "sensor",
        "object_suffix": "RT",
        "config": {
            "device_class": "precipitation",
            "name": "Rain Total",
            "unit_of_measurement": "mm",
            "value_template": "{{ (float(value|float) * 25.4) | round(2) }}",
            "state_class": "total_increasing"
        }
    },
...
    "rain_in": {
        "device_type": "sensor",
        "object_suffix": "RT",
        "config": {
            "device_class": "precipitation",
            "name": "Rain Total",
            "unit_of_measurement": "in",
            "value_template": "{{ value|float|round(2) }}",
            "state_class": "total_increasing"
        }
    },

But what I'm not clear about is what happens when the device uses metric units.

[zuckschwerdt]

Your "rain_in" entry looks good, the "rain_mm" one should not be changed and is not used in your case, you always get rain_in messages.

[shampeon]

PR up: #2801

[gdt]

With the PR being merged, is this discussion now about a fixed bug and should it be closed? Or is there something else?

[shampeon]

The rain_in sensor now reads the correct values. But I've also noticed rain_rate_in_h has the incorrect unit_of_measurement and value template formula:

    "rain_rate_in_h": {
        "device_type": "sensor",
        "object_suffix": "RR",
        "config": {
            "device_class": "precipitation_intensity",
            "name": "Rain Rate",
            "unit_of_measurement": "mm/h",
            "value_template": "{{ (float(value|float) * 25.4) | round(2) }}",
            "state_class": "measurement"
        }
    },

[zuckschwerdt]

Fixed with 7f60fff