Suppress NaN Readings from Log with RegEx

[ukiews]

Is it possible to suppress NaN readings from the log when using regex to get sensor values.

I am using a Shelly device with the Add-On and sensor for temp and humidity readings.
The values are published under the same topic, but they are only reported when the temp or humidity changes.
So the log is full of NaN readings when no value is reported:

[1/4/2025, 12:01:21 AM] [homebridge-mqttthing] This plugin generated a warning from the characteristic 'Current Relative Humidity': characteristic value expected valid finite number and received "NaN" (number). See https://homebridge.io/w/JtMGR for more info.
[1/4/2025, 12:01:21 AM] [homebridge-mqttthing] This plugin generated a warning from the characteristic 'Current Relative Humidity': characteristic value expected valid finite number and received "NaN" (number). See https://homebridge.io/w/JtMGR for more info.
[1/4/2025, 12:01:24 AM] [homebridge-mqttthing] This plugin generated a warning from the characteristic 'Current Relative Humidity': characteristic value expected valid finite number and received "NaN" (number). See https://homebridge.io/w/JtMGR for more info.
[1/4/2025, 12:01:24 AM] [homebridge-mqttthing] This plugin generated a warning from the characteristic 'Current Temperature': characteristic value expected valid finite number and received "NaN" (number). See https://homebridge.io/w/JtMGR for more info.
[1/4/2025, 12:01:24 AM] [homebridge-mqttthing] This plugin generated a warning from the characteristic 'Current Relative Humidity': characteristic value expected valid finite number and received "NaN" (number). See https://homebridge.io/w/JtMGR for more info.

[GithHobby]

Hi @ukiews I receive also these warning with add-on but not for the humidity.
Which sensor do you use?
Have you checked the valued sent from shelly?

[ukiews]

DHT22 with the S1PMG3

[GithHobby]

I use also the DHT22 but seems not very good.
You should try to log the values. Maybe sometimes you should receive a wrong value.

Could you do that?

[ukiews]

My log above just shows humidity, but the issue occurs with both temp and humidity. The values report correctly to HomeKit. The problem is that shelly only reports the values when there is a change in temp or humidity. So the plugin log is filled with NaN entries. Could there be an option added to the plugin to suppress these errors? Technically, they are not errors, the values simply have not yet been pushed.

[GithHobby]

The Shelly send the message to the MQTT broker.
The broker send the message to the subscribers as mqttthing plugin.
The problem is in the values.
The log show you the mqttthing warning but not the valued received (e.g. if you publish the value of 300 the log should add a NaN warnings)
I suggest you to log the values in the MQTT broker (I use a python script but it is possible to use app like MQTTexplorer that log the values).

Otherwise I don't have other solution to you. Sorry.

[ukiews]

Could you elaborate what you mean by “log the values” in mqtt broker? I am running mosquito on the rasPi.
Are you saying the mosquito could somehow suppress this warning?

[GithHobby]

No, mosquito just dispatch the messages and for it the message is a text
You could use the mosquito client or write few python lines to log the values.
Remember to add the timestamp and compare with the mqttthing log to discovery what is wrong.

[ukiews]

Sorry, I'm still not completely following.
As I mentioned in the OP, the Shelly device only publishes the temp and humid values when they are updated. This is what is 'wrong.'
What I am requesting is an option that would ignore mqtt messages that results in regex failing to 'find' the expression specified.

For example, I use the expressions: AtticFan/events/rpc$.params["humidity:100"].rh and AtticFan/events/rpc$.params["temperature:100"].tF to extract the humid and temp values.
However, the 'AtticFan/events/rpc' topic itself is updated more frequently than the temp and humid values are published to it, so that the current temp/humid values are not present in the topic unless there is an actual change in temp or humid. This was verified using MQTT Explorer.

[GithHobby]

Sorry @ukiews but I'm confused.

The mqttthing log show you NaN warning message.
You want to solve this warning on the plugin side and not in the sender (shelly).

Is it right?

[ukiews]

Correct. I cannot solve it on the Shelly side. This is just how Shelly with the Add-on module updateds mqtt topics.

[GithHobby]

I'm sorry but I don't know how to modify the mqttthing code.

On the Shelly side I make a script for send the value to a selected topic with the right value.
So I should be able to modify on the shelly side

[ukiews]

Could you please share the script you’re using on Shelly side?

[GithHobby]

sure!!
I have also one photo diode in the analogue input for the light.

let CONFIG = {
  inputID: 100, 
};

Shelly.addEventHandler(function (event) {

  if (event.info.component === "temperature:"+CONFIG.inputID) {
    if (event.info.event === "temperature_change") {
       MQTT.publish(topic_t, JSON.stringify(event.info.tC), 2, true);
    }
  } else if (event.info.component === "humidity:"+CONFIG.inputID) {
    if (event.info.event === "humidity_change") {
       MQTT.publish(topic_h, JSON.stringify(event.info.rh), 2, true);
    }
  } else if (event.info.component === "input:"+CONFIG.inputID) {
    if (event.info.event === "analog_change") {
       MQTT.publish(topic_l, JSON.stringify(event.info.percent), 2,true);
    }
  }

});

let topic_t = "TenDomus/sensors/temperature";
let topic_h = "TenDomus/sensors/humidity";
let topic_l = "TenDomus/sensors/light";