mqttclient | platform MQTT client | Runtime Evironment library

I state that this is the first time I use Kivy. The code I attached works, the only problem is that the lbl label does not update automatically but only if I press the update button. In practice, if I call the update_lbl function via the "update" button it works, when it is called automatically by unpacking_msg it does nothing.

First of all, I am a far cry from a being an experienced programmer, so please forgive me if I am asking beginners question here.

I encountered a problem trying to publish a payload using the PubSubClient on an ESP8266. I am using VS Code with Platformio.

During Build I receive the following error. It seems like the PubSubClient is trying to convert the payload from char to unsinged int, even though the payload is defined as const char in the API of the PubSubClient library.

I want to connect my backend on Spring boot to one of the devices in my hardware setup in Google Cloud Iot-Core. I basically copied this github repository and adjusted the authentication and connection options. When I run my program it throws this exception:

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.eclipse.paho.client.mqttv3.MqttClient]: Factory method 'connectToMqttClient' threw exception; nested exception is Incorrect username or password (4)

To create password I use this method

I have a node.js file that subscribes to a topic and upon receiving a published message scans a local mysql db for the most recent entry in a variable named "command". Command values will trigger various responses, but I have left this portion out since my issue is before this.

My mysql query appears to be giving me errors. I am trying to look for the most recent entry of the command column and assign the value to a var command. I thought this code would do the trick:

I publish 1000 messages from an MQTT Server when a client subscribes to a topic. Some of the messages are not received by the MQTT Client. Is this a bug or am I implementing something wrong?

Here are the server and client configuration examples.

I'm using the HiveMQ library in my Java Spring application to connect to a Mosquitto instance as I find it more user-friendly compared to the Paho client. But something is going wrong with the automatic reconnection. From time to time the connection is lost and the application doesn't succeed in reconnecting (see logs 1). This can also be triggered by restarting the Mosquitto broker itself (see logs 2).

This is my client builder code with additional logging in the disconnect to check if the credentials are still correct:

I was working on Flutter Aws IoT App

I was able to connect and get data from the server.

I would like to get the proper data.

Here is the data on my Aws

Here what I receive in Flutter

I have wriiten to publish a rfid value and while subscribing inside javascript, the socket connection is lost and I have attached the screenshot of my console.

value.php

Good afternoon. I got this Alexa skill class, inside this class I send and receive messages using mqtt. Unfortunately for this library, the mqtt message needs a callback. Here is my code: