MySensors distance sensor unit_of_measurement configuration

Configuration
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1

I have successful connected two mysensors distance nodes + mqtt gateway and I’m seeing them in HA.
I see the correct values when I use the MQTT tab in the Developer Tools.
The two sensor nodes do have the same sketch (except node_id) and are outputting their values in cm.

When I look in the tab States in the Developer Tools, I see my two mysensor nodes.
But one has unit_of_measurements: cm and the other unit_of_measurements: m

I have only configured the mysensors entry in the configuration, the sensors are autodetected by HA.
So why two different units of measurement?
Where can I configure this?
Is it set in the mysensor1.pickle file?

2

First off all, check the autodiscovery messages mysensors sent. HA uses whatever the autodiscovery messages sent.

3

That is just the question, the nodes sketch code is identical except the node_id.
Yet HA gives them a different unit_of_measurement.

Mysensors units
Mysensors units902×414 29.2 KB

From what I can read in the mysensors docs, the unit is not sent to the controller during the presentation.
So where does this data comes from? I could imagine a default value, but why different?

I’ve changed the persistence file from pickle format to json format to be able to read it, but this unit_of_measurement is not mentioned inside this file.

4

Ok, found the solution.

I digged into the code dev branch of home assistant and found following file in \home-assistant\components\sensor\mysensors.py
In this file the defaults for each type op sensor are defined in an array.

SENSORS = {
    'V_TEMP': [None, 'mdi:thermometer'],
    'V_HUM': ['%', 'mdi:water-percent'],
    'V_DIMMER': ['%', 'mdi:percent'],
    'V_LIGHT_LEVEL': ['%', 'white-balance-sunny'],
    'V_DIRECTION': ['°', 'mdi:compass'],
    'V_WEIGHT': ['kg', 'mdi:weight-kilogram'],
    'V_DISTANCE': ['m', 'mdi:ruler'],
    'V_IMPEDANCE': ['ohm', None],
    'V_WATT': ['W', None],
    'V_KWH': ['kWh', None],
    'V_FLOW': ['m', None],
    'V_VOLUME': ['m³', None],
    'V_VOLTAGE': ['V', 'mdi:flash'],
    'V_CURRENT': ['A', 'mdi:flash-auto'],
    'V_PERCENTAGE': ['%', 'mdi:percent'],
    'V_LEVEL': {
        'S_SOUND': ['dB', 'mdi:volume-high'], 'S_VIBRATION': ['Hz', None],
        'S_LIGHT_LEVEL': ['lx', 'white-balance-sunny']},
    'V_ORP': ['mV', None],
    'V_EC': ['μS/cm', None],
    'V_VAR': ['var', None],
    'V_VA': ['VA', None],
}

So for V_DISTANCE the default is ‘m’.
Seeing that the penny dropped finally. The first sensor is one that I activated one year ago.
The second is the one I activated this weekend.
I updated also the first one with the latest mysensor lib 2.3.2 to be sure that the sketch code of the two sensors was identical.
I forgot that I did a customisation of the auto detected sensor, I changed the default ‘m’ to ‘cm’ in my case because the sensors are outputting centimeters.
:man_facepalming:

5

Can happen. Always document your changes for later :slight_smile:

6

HI @evb, could you share your mysensors code?
I will use a ultrasound proximity sensor to measure a cistern water level, and once I use hass as well, I think your code will save me many hours trying to adapt codes to work with hass!!!

Thanks

7

@oliverdog I have putted my Mysensors sketches online on Github : GitHub - ericvb/MySensorsArduinoSketches: MySensors Arduino sketches running at my home

You will find the specific ultrasonic sketch here : MySensorsArduinoSketches/sketches/ArduinoUltrasonicSensorWithEncryptionNewPingMedianGithub at master · ericvb/MySensorsArduinoSketches · GitHub

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