Nodered Virtual sensor

[Woodpeckercz]

Hi,
first of all great work.
I would like to take some of my existing mqtt sensors, connected to my mqtt broker and home assistant.
For example my hot water tank temperature sensor and add it to vrm.
Your driver seems like ideal solution.
How would I go about creating a flow in nodered to create a virtual sensor/bridge over to dbus?

[freakent]

H, thanks for the feedback. A number of the folks who use this driver do so with NodeRed. I don't have a suitable NodeRed installation setup at them moment to provide an example. Hopefully someone else monitoring this project can provide an example.

[Woodpeckercz]

I managed to register the NodeRed "virtual" device, and it shows up in the console but with blank temperature.
I missunderstood how the registration process works.
Now I'm trying to figure out how to update the temperature.

[Woodpeckercz]

got it working now by manualy publishing a message with {"value":11} payload to topic W/PortalID/temperature/UnitID/Temperature.
Now I just need to automate it within nodered and refine the incomming sensor message.

[freakent]

I highly recommend you use MQTT Explorer to experiment with registration procedure before moving what you have learned to NodeRed.

[freakent]

Also take a look at the samples in the test-data folder. They are written in python but should be very easy to follow.

[Woodpeckercz]

thanks, I'm using mqtt explorer.
I'm strugling with converting the mqtt input into JSON string that the system will accept and change the value,
Basicly,
I need to convert this:

{"battery":83,"humidity":60.41,"last_seen":"2023-10-16T23:26:46.650Z","linkquality":69,"power_outage_count":6,"pressure":1008.9,"temperature":19.02,"voltage":2975}

into this:

{"value":19.02}

[Woodpeckercz]

Figured it out now.

First I subscribe to the sensor topic with MQTT In, then I used the Change node to Set the msg.payload to {"value": msg.payload.temperature} and use the MQTT Out to publish to W/PortalID/temperature/UnitID/Temperature topic