You might also want to set the MQTT output to 'attribute_and_json' so that you get individual sensor data as well as the combined object. See down the bottom of MQTT | Zigbee2MQTT
If you install MQTTExplorer on your PC and connect to the MQTT broker then you can easily see all the topics that your device publishes to.
I recommend setting up Friendly Names for the sensors in MQTT, it makes life much easier, and also means you just have to change the device ids in the conf file if you have to change a device. Node red does not need to use the device ids directly.
In case you didn't know, zigbee2mqtt comes with a useful web front end at IP:8080, where you can setup the friendly names, see a device map and other things. You may have to enable the frontend in the conf file.
[Edit] Oh, I see you have already found the web i/f
well.. turned out I found the time to investigate further. And in the end I don't even need to use the mqtt node, because using mqtt instead of deconz has solved my intial issue.
now in the attributes of the payload I see everything related to the actual device triggering the flow , incluing the illuminance_lux value
Regarding what you wrote above, yes I do know the webui. I have also edited the firendly name directly from the devices.yaml file. However what I have noticed (and i don't like) is that HA does not pick up the friendly name to name entity ids. I had to override them one by one manually otherwise in Node-Red I'd see the guid ids generated by mqtt instead of the friendly names
At this moment I've problems with my Central Heating.
So my idea is, when I'm abroad, to send an email with some information about all the temperatures.
The title of the email could be "Temperatures dropped".
The body of the email should be something like:
The temperature in the living is 15°C
The temperature in the kitchen is 10°C
The temperature in the boiler is 11°C
etc.
And of course, the temperature values are coming from some sensors in my Home Assistant
As mentioned, today I can already send an email notify with only a text message, like:
{
"title": "Verwarming",
"message": "Temp. boiler warm water te laag"
}
But, I don't arrive to concatenate the explaining text with the corresponding sensor values
I am still not sure what question you are asking? Are you able to get the values from HA? If that is the problem then you would probably be better asking on an HA forum.