Steve’s Guide to Networking, IoT and the MQTT Protocol

Welcome to Steve’s Guide to Networking and IoT, your ultimate resource for mastering internet technologies, networking protocols, and IoT systems.

Whether you’re a beginner eager to understand the basics or a professional looking to expand your technical expertise, this guide offers clear, practical tutorials with a particular emphasis on networking protocols and the Internet of Things (IoT).

Key topics covered include:

MQTT Protocol: Detailed analyses of MQTT protocol packet structures, security mechanisms, and practical applications such as sending and receiving JSON data over MQTT with Python.

MQTT-SN Protocol:Detailed analyses of MQTT protocol packet structures, and example usage using the Python client.

IPv4 Addressing: An exploration of IPv4 address classes, their usage, and special IP addresses.
Steve’s Internet Guide

DNS: Beginner-friendly guides explaining the Domain Name System (DNS) and its role in translating domain names to IP addresses.
Steve’s Internet Guide

IoT Networking and Messaging Protocols: Overviews of networking and application protocols commonly used in IoT development.

Learning Approach:

The site prioritizes a hands-on, example-driven learning methodology, ensuring users can immediately apply what they learn. Tutorials include clear explanations, diagrams, code snippets, and downloadable resources to reinforce understanding.

Audience:

Steve’s Internet Guide is ideal for:

  • Network engineers and IT professionals.
  • IoT developers and enthusiasts.
  • Students and hobbyists eager to learn networking and internet technologies.

This site and newsletter is dedicated to help you learn and master basic networking, protocols like MQTT and MQTT-SN , and use them in your IoT applications.

Sign Up for Steve’s Latest Posts and stay in touch.

Getting Started With MQTT

I Recommend you start your journey into MQTT with the short MQTT course.

Projects

I am constantly working on IOT/MQTT educational projects which I share on my projects page.

I do also undertake commercial projects from time time. If you need assistance then please use the ask steve page

Latest Posts

How to use the Mosquitto Broker with IPv6

mosquitto-ipv6You can connect to the Mosquitto broker using IPV6 as well as IPv4 provided IPv6 is enabled on your machine.

When you start mosquitto using a basic configuration file like the one shown below mosquitto will listen for connections on both  IPv4 and IPv6. (more…)

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Using the ArduinoMQTT Client Library

arduinoThere are several  MQTT clients available for Arduino and we are going to use the PubSub MQTT client.

Before you can use this client you need to install it into the Arduino Library.

Go to the Library manager and so a search for MQTT. You will find quite a few listings scroll down the select the ArduinoMQTT client. (more…)

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MQTT C client – Connect, pub and subscribe,Single Thread

mqtt-c-clientIn This tutorial we will look in more detail on how to connect , publish and subscribe using the MQTT v 3.1.1 client synchronous client using a single thread.

We will not be using callbacks. If you use callbacks then second thread is started automatically to process the callbacks. (more…)

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MQTT-SN QOS 3 to MQTT Gateway Using Node-Red

MQTT-SN works in a similar manor to MQTT and normally requires a connection to a broker/gateway before it can exchange messages.

MQTT-SN uses UDP which is a connectionless protocol the connection is actually a virtual connection.

However because MQTT-SN uses UDP , MQTT-SN also provides the ability to publish message without requiring a connection to a broker or gateway using a message with a QOS of 3 or -1.

(more…)

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Connect Using MQTTv5 and the Python MQTT Client

In this tutorial we will look at how you connect to a broker using MQTTv5.

The tutorial assumes you are already familiar with the basics after using MQTTv3.1.1.

This is covered in this tutorial:

The main changes to take into account when moving your code to MQTT v5 are the properties object and increased reason codes. (more…)

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Converting JSON to CSV with Python

JSON formatted data is a common way of sending data over MQTT.

Storing the data directly as JSON formatted data is also common

However it is also very common to store this data as CSV or a least convert it to CSV for use in legacy systems. (more…)

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How to Use the Python MQTT Client with a Backup Broker

Introduction

In this project guide we will be developing python scripts to use a backup broker to publish and receive messages to improve message reliability in failure situations.

MQTT offers three QOS settings -0,1,2 as described in the understanding QOS tutorial.

QOS levels 1 and 2 require an acknowledgement from the MQTT broker and provide for reliable message transfer.

However there are many circumstances were just relying on these QOS levels isn’t sufficient. (more…)

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Receiving Messages with The Paho node.js MQTT client

receiving-messages-nodejsMessages are received by processing the message event.The format is:

function (topic, message, packet) {}

Example code is shown below:

//handle incoming messages
client.on('message',function(topic, message, packet){
	console.log("message is "+ message);
	console.log("topic is "+ topic);
	console.log("packet =" +JSON.stringify(packet));
	console.log("packet retain =" +packet.retain);
});

(more…)

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Using MQTT Explorer

mqtt-explorerMQTT explorer is a free cross platform MQTT client that is very useful for MQTT testing.

You can download the client here.

The client lets you subscribe to topics and publish messages to topics using a graphical interface.

In addition is shows retained messages and allows you to easily delete them. (more…)

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You will find All the latest Tutorials on the blog