Automation to check how often MQTT messages are sent

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1

Hi everyone,
I’ve about 10 arduinos scattered all over the home with many sensors connected.
They communicate through MQTT with Home assistant.
It sometimes happens that some sensors or arduinos stop working/communicating.
Now every arduino has a buzzer that sounds when there’s a problem. Unfortunately, it’s quite annoying when it happens in the middle of the night…
Consequently, I want to check that everything is ok from HA.
How can I create an automation that checks the time spent between 2 messages?
For example: every arduino should send a MQTT message every 60 seconds, I’d like to create an automation that triggers when the time spent is more than 180 seconds.

Thanks in advance!

2

Have a look at implementing last will and testament (LWT) mqtt messaging on your arduinos.

You can then automate sending messages if one of them goes off line unexpectedly.

https://www.hivemq.com/blog/mqtt-essentials-part-9-last-will-and-testament/

3

It might be a good alternative so than I can create simple automation on a flag status.
What does it happen when a sensor connect and disconnect multiple times (wifi connection not good)?
Is the LWT message sent anytime or if the sensor connects within the keep-alive period nothing will be sent?

Thanks!