Simultaneously support different MQTT payload formats (regular, as well as JSON)

[kbahey]

I have been using MQTTSubscribe for a few years, so many thanks for a valuable component that enables Weewx to work with any weather sensor.

There is a limitation that the message type must apply to all sensors, like so:

[[message_callback]]
  type = json

That worked well when my outdoor and indoor sensors were both JSON.
My outdoor station is Acurite, and it feeds JSON data Home Assistant.

home/climate/1111-56 
{
"time":"2024-12-20 10:12:00",
"model":"Acurite-5n1",
...
"wind_avg_km_h":5.139,
"temperature_C":-3.77778,
"humidity":96, ...
}

My indoor sensor was a custom one based on a BME280 connected to an ES32.

Then, I replaced the indoor sensor with an AirThings Wave Plus and its MQTT format is like this:

airthings/60:98:66:xx:xx:xx/temperature '21.4'
airthings/60:98:66:xx:xx:xx/humidity '41'

Now it is impossible to feed indoor data to MQTTSubscribe, because the message type is defined globally, and applies to all topics/sensors.

Is it possible to define the message type per topic, or per sensor?

[bellrichm]

As of release 2.1, there is a construct.

[[topics]]
    [[[topic-name]]]
        [[[[message]]]]
            type = json | keyword | topic

For more information see, https://github.com/bellrichm/WeeWX-MQTTSubscribe/wiki/Common-Options#the-message-sections

[kbahey]

Thanks a lot.
This means that I can finally get back indoor data into Weewx.

A couple of questions:

a) Is "individual" supported as a type, or only "keyword", "topic" and "json"?

b) The examples here imply a different hierarchy than what is in your reply.

With only 3 square brackets for message, then a list of topics for that type.

Like this:

    [[topics]]
        [[[message]]]
            type = individual
        [[[airthings/60:98:66:xx:xx:xx/temperature]]]
            name = InTemp
            conversion_type = float
            units = degree_C

        [[[message]]]
            type = json
        [[[home/climate/1111-56]]]
            [[[[temperature_C]]]]
                name = outTemp
                conversion_type = float
                units = degree_C

Can you please clarify?

[kbahey]

I got the json topics working, because it is obvious what their fields are.

Like this:

    [[topics]]
        unit_system = metric

        [[[home/climate/1111-56]]]
            [[[[message]]]]
                type = json

            [[[[temperature_C]]]]
                name = outTemp
                ignore = False
                contains_total = False
                conversion_type = float
                units = degree_C

            [[[[humidity]]]]
                name = outHumidity
                conversion_type = int

            [[[[time]]]]
                ignore = True
            [[[[model]]]]
                ignore = True

        [[[home/climate/1111-49]]]
            [[[[message]]]]
                type = json

            [[[[wind_avg_km_h]]]]
                name = windSpeed
                conversion_type = float
                units = km_per_hour

            [[[[wind_dir_deg]]]]
                name = windDir
                conversion_type = int

            [[[[rain_mm]]]]
                name = rain
                conversion_type = float
                contains_total = True
                units = mm

            [[[[time]]]]
                ignore = True
            [[[[model]]]]
                ignore = True

All the above works as intended, with data flowing through from the weather station through MQTT to Weewx.

But for the other MQTT format (type = individual), I can't figure out what the field name should be?

I have it currently like this, with no field name, because individual does not have a field name like json.

        [[[airthings/60:98:66:xx:xx:xx/temperature]]]
            [[[[message]]]]
                type = individual
                name = inTemp
                conversion_type = float
                units = degree_C

And no data comes through for the inTemp.

How should I proceed with this?

[bellrichm]

Yeah, topic was a typo.
That looks correct. At this point, set debug = 1 and attach the log. It should show the data coming in and how MQTTSubscribe is processing it.

[bellrichm]

Oh I think I see it. Try this. It might work. I might have to do some experimenting.

        [[[airthings/60:98:66:xx:xx:xx/temperature]]]
                name = inTemp
                conversion_type = float
                units = degree_C
            [[[[message]]]]
                type = individual

[kbahey]

That worked!

Thank you so much.

It is best if the the above config snippets go into the Wiki.

[bellrichm]

Good to hear.
Maybe updating https://github.com/bellrichm/WeeWX-MQTTSubscribe/wiki/individual-example to move the message section would help. The challenge is there are so many configuration possibilities….
I’m still trying to get v3 out the door, after that I might have time to revisit the wiki/documentation.

[kbahey]

Another suggestion:

In the documentation, mention that this global configuration part is no longer recommended (i.e. will still work, but should be replaced by the topic message syntax):

    [[message_callback]]
        type = json

Then in all the examples, add the following syntax for each topic.

    [[[[message]]]]
        type = json

Or

    [[[[message]]]]
        type = individual

That should work for all the new configurations, while those who use the older global type syntax will be unaffected.

[bellrichm]

In the reference documentation, https://github.com/bellrichm/WeeWX-MQTTSubscribe/wiki/Common-Options, there is no mention of message_callback. In the log, there is a warning that is deprecated.
In, https://github.com/bellrichm/WeeWX-MQTTSubscribe/wiki/Common-Options, the [[[topic-name]]] [[[[message]]]] had a todo. I removed that, and added some documenation.
The json example still needs to be updated to remove message_callback.
Next will be to add an example with different ‘topic types’ (message under the the topic-name)
I think that should do it.