Understanding And Using MQTT v5 Request Response

Web Applications have a direct connection between the sender and receiver. The sender is the client (web browser) and the receiver is the server. They implement a command response message flow were the client(browser) makes a request and the server responds and there is a direct connection between client and server.

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MQTT v 5.0 New Features Overview

MQTT v5 introduced many new features and changed how some existing features work. In this tutorial I will be covering all of these features with brief examples, and also in many case, links to detailed examples and videos.

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How MQTT Works -Client Connections

MQTT is a messaging protocol i.e it was designed for transferring messages, and uses a publish and subscribe model. This model makes it possible to send messages to 0,1 or multiple clients.

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Public MQTT Brokers and Reserved Topics – Discussion Post

Preface This is a discussion post and these are currently my thoughts on this topic. I would be grateful for comments and feedback. Introduction MQTT is still in the early stages of deployment and currently is used only on private networks. However with the growth in the adoption of the MQTT protocol for information distribution the number of public brokers and topics will probably increase substantially just as happened with websites in the early days of the internet.

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Using the Paho Node.js MQTT Client-Starting Guide

The node.js MQTT client is an open source client that can be used for publishing messages and subscribing to topics on an MQTT broker. It  can be installed using: npm install mqtt –save and npm install mqtt -g To install the command line tools Documentation for the client is available here

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Configuring the MQTT Publish and Subscribe Nodes in Node-Red

Node-Red provides both an MQTT subscribe (input) and publish (output) node. The configuration for these nodes are almost Identical as the main part of the configuration concerns the actual client connection. Because of this it is useful to think of the publish and subscribe nodes as consisting of two components as shown in the schematic below: Before we look a the actual configuration we will look at MQTT client connections in general.

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Logging MQTT Sensor Data -Notes

Data from sensors will need to be stored. But how much data do you really need to store? Many sensors like state sensors (ON/OFF), temperature etc will fluctuate very little over the course of a day so does it makes sense to store the same sensor value every x seconds?

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