This codelab introduces the fundamental concepts of the Internet of Things (IoT), its real-world applications, and how to set up an MQTT broker using Mosquitto. You will also learn how to subscribe to and publish messages on MQTT topics and watch me demonstrate a simple IoT project.

What you'll learn

• Real-world IoT use cases.
• How to set up Mosquitto MQTT broker.
• Subscribing and publishing using MQTT.

The Internet of Things (IoT) is the network of physical objects or "things" embedded with electronics, software, sensors, and network connectivity, which enables these objects to collect and exchange data.

IoT is transforming many industries with innovative applications. Here are a few examples:

Smart Home & Consumer Devices

• Smart Thermostats (e.g., Nest, Ecobee)
• Smart Lighting Systems (e.g., Philips Hue)
• Voice Assistants (e.g., Amazon Echo, Google Home)
• Smart Locks (e.g., August, Yale)
• Smart Refrigerators (e.g., Samsung Family Hub)

Healthcare

• Wearable Health Trackers (e.g., Fitbit, Apple Watch)
• Remote Patient Monitoring Systems
• Smart Pill Bottles (e.g., AdhereTech)

Industrial IoT (IIoT)

• Predictive Maintenance in Manufacturing
• Smart Robotics in Factories
• Supply Chain Management

Smart Agriculture

• Precision Farming
• Livestock Monitoring
• Automated Irrigation Systems

Smart Cities

• Smart Traffic Management Systems (e.g., Siemens Mobility)
• Smart Parking Solutions (e.g., ParkMe)
• Waste Management Systems (e.g., BigBelly)
• Smart Street Lighting (e.g., Philips CityTouch)

Energy Management

• Smart Meters (e.g., Itron)
• Solar Panel Monitoring (e.g., SolarEdge)
• Smart Grid Management

Retail & Customer Experience

• Beacon Technology (e.g., Apple's iBeacon)
• Smart Shelves (e.g., Kroger's Edge Shelving)
• Automated Checkout Systems (e.g., Amazon Go)

Transportation & Logistics

• Fleet Management Systems (e.g., Samsara)
• Connected Cars (e.g., Tesla)
• Cargo Monitoring (e.g., Maersk)

Environmental Monitoring

• Air Quality Monitoring (e.g., AirVisual)
• Forest Fire Detection Systems
• Smart Water Management (e.g., Neptune)

Devices and Sensors

• Sensors detect changes in the environment (e.g., temperature, humidity).
• Actuators perform actions (e.g., turning on lights).

Communication Protocols

• MQTT: Lightweight messaging protocol for IoT.
• HTTP: Common but more resource-intensive.

Data Storage and Analysis

• SQL / NoSQL Database storage
• Data analysis providers (cloud services, closed-sourced)

MQTT (Message Queuing Telemetry Transport) is a lightweight protocol designed for IoT. It follows a Publish/Subscribe model:

• Publisher: Sends messages to a topic.
• Subscriber: Receives messages from a topic.
• Broker: Manages the topics and routes messages.

Follow the instructions in the relevant section to download and install the broker. The categories of the lab will include the instructions for Linux and Windows but for more operating systems, visit the Mosquitto Website

Install Mosquitto (Ubuntu Linux)

Install Mosquitto on Linux using the following command:

sudo apt-get update
sudo apt-get install mosquitto mosquitto-clients

Install Mosquitto (Windows)

Install Mosquitto on Windows using the following steps:

1. Visit the Mosquitto Website
2. Download the binary
3. Run the installer
4. Add the path to your environment variable

We would be using the mosquitto_sub command to subscribe to a topic. Use the following command to subscribe to a topic called "test"

mosquitto_sub -i 813117992 -t "test" -d

The flags passed are as follows:

i – Client id. If this parameter is not passed, client ID is generated automatically.

t – Name of the topic to subscribe to.

d – Enables printing of debug messages.

h – Hostname (optional). THis defaults to localhost

p – Port (optional, note the lowercase p). This defaults to 1884

u – username. Username (optional). Only used if auth is required

P – password. Password (optional, note the uppercase p). Only used if auth is required

# Example of a full command with all parameters
mosquitto_sub -i 813117992 -t "test" -d -h 192.168.100.223 -p 2534 -u kwasi -P password123 

We would be using the mosquitto_pub command to publish a message on a topic. Use the following command to publish to a topic called "test"

mosquitto_pub -i 813117992 -t "test" -m "Test yesterday was so EZ. We cooked" -d

The flags passed are as follows:

i – Client id. If this parameter is not passed, the server generates client ID automatically.

t – Name of the topic to which the message is published.

m – Text payload of the message to be published.

d – Enables printing of debug messages.

h – Hostname (optional). THis defaults to localhost

p – Port (optional, note the lowercase p). This defaults to 1884

u – username. Username (optional). Only used if auth is required

P – password. Password (optional, note the uppercase p). Only used if auth is required

# Example of a full command with all parameters
mosquitto_pub -i 813117992 -t "test" -m "Nah bro. I'm cooked fr." -d -h 192.168.100.223 -p 2534 -u kwasi -P password123