Reduce Frequency of MQTT Publish Events

[joekob]

Hello,

I am using Tasmota 9.2.0 with about 20 switches (mostly Shellys) and another 20 sensor nodes. All those nodes are linked to a Homeassistant installation running a mosquitto MQTT broker on a Raspberrry Pi. From the MQTT broker I am currently feeding the sensor data via Node-RED into a mariaDB database for further longterm evaluation. This setup works just fine and the stability of the Tasmota powered devices is amazing!! 👍

Nevertheless I see that the nodes are are publishing updates multiple times per minute and if I channel all these updates directly into the database it grows very big in a short period of time. And since the pressure or the outside temperature do change in much longer intervals this is not necessary. I can filter the input via Node-RED but I think the better way would be to reduce the frequency of sensor data updates published to the MQTT broker - since this would reduce traffic and power consumption.

I saw the topic #10323 dealing with a setup of Domoticz and read about the TelePeriod parameter but this does not solve my issue - I guess - because it sets the maximum time interval for an update as far as I understand. Ideally I would like to achieve something like "send only if the value changed by X or if the last publish is at least Y seconds ago". But even a fixed update period would be OK for me.

What am I missing? Or is it necessary to publish only via rule?

Suggestions are much appreciated!
Joe

[sfromis]

"Multiple times per minute" sounds like you have a lower TelePeriod than the default of 5 minutes (which generally makes sense for environment sensors). What value do you have?

[meingraham]

It might also be that your sensors are reporting changes in readings that often. This could be due to the resolution setting (number of decimal places) which means even a thousandth difference could generate a telemetry update. For some sensors there are delta thresholds you can set.

As @sfromis mentioned, check your TelePeriod setting on each of the devices where a sensor is connected. But also, if you can post some of the MQTT messages that are being logged, we may be able to pin down which of these is the reason and perhaps be able to make changes to the sensors' settings to reduce some of the messages.

[joekob]

Thanks for the very quick answers!
I just checked my configuration:

TelePeriod = 300
HumRes = 1
TempRes = 1

These are the defaults I guess. BUT, looking at the log and trying to figure the exact interval I probably saw my error: I am deriving the values from the STATUS10 / StatusSNS from the stat-topics. These get updated approx. every 8s. The tele/SENSOR topic follows the TelePeriod interval - I changed it and works as expected. Sorry for being so blind...

BTW: Is there a possibility to reduce the frequency of publishing the stat-topics as well?

[barbudor]

STATUS10/StatusSNS is published on demand
So if you have so many it is because something is asking for it, not Tasmota

[meingraham]

Are you running TasmoAdmin?

[joekob]

Yes, I do run TasmoAdmin....and that is the source for the demands barbudor mentions.
Looking into the configuration of TasmoAdmin: Update frequency 8 seconds - sounds familiar...
Thanks!! Puzzle solved.