Hands-on ESP32 with Arduino IDE: Unleash the power of IoT with ESP32 and build exciting projects with this practical guide

Hands-on ESP32 with Arduino IDE

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First published: January 2024

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Published by Packt Publishing Ltd.

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ISBN 978-1-83763-803-1

www.packtpub.com

Dedicated to my parents, Zulfiqar Ahmed and Aneela Zulfiqar, as well as my wife, Alfiya Shaikh, for their continuous support and encouragement.

Contributors

About the author

Asim Zulfiqar is a blogger and tech content creator who has been writing tutorials on embedded systems and the IoT on his blog and YouTube channel, High Voltages. Currently, he is working as a scientific programmer for IoT research projects.

He completed his bachelor’s degree in electronic engineering at Sir Syed University of Engineering and Technology, Pakistan. After that, he completed his Erasmus Mundus joint master’s degree program in photonics integrated circuits, sensors, and networks at Scuola Superiore Sant’Anna (Italy), Aston University (UK), and Osaka University (Japan).

I express my sincere gratitude to my parents and family for their continuous support and encouragement during this project.

I would also like to extend my thanks to Uma Devi, Suwarna Patil, Sayali Pingale, Aryaa Joshi, Shagun Saini, and the entire Packt team for their invaluable guidance throughout this project, as well as Kalbe Abbas and Vishwavardhan for their technical insights.

About the reviewers

Vishwavardhan Yeseskar has worked in the design and development of embedded systems for more than 12 years, especially focused on IoT. He has work experience with some of the best German companies in this domain, and he has been a part of teams that have rolled out multiple embedded devices with IoT integration.

He has a bachelor’s degree in electronics and communication from Visvesvaraya Technological University and a postgraduate diploma in artificial intelligence and machine learning from Amity University. He is currently employed as a product architect at a leading German firm.

I would like to thank my wife, who encouraged me to contribute to the learning community by active participation, and also for her patience during the period of review of this book.

Kalb e Abbas, Jafferi is an embedded systems engineer with more than five years of experience working in the embedded systems domain. His main interest is creating networks of devices using wireless technologies such as BLE, Wi-Fi, and LPWAN, and monitoring these devices remotely.

He has collaborated with many web and application developers that required integration of data collection and monitoring using embedded devices.

I am indebted and thankful to my parents, friends and colleagues, and all the employers who saw potential in me and always made me feel special.

I am very much thankful to the author of the book and my friend, Asim Zulfiqar. His knowledge, experience, and humbleness have inspired me in many ways.

Table of Contents

Preface

Part 1 – Introduction: Getting Familiar with ESP32

1

IoT with ESP32 using Arduino IDE

A brief introduction to IoT

IoT and its main characteristics

The basic architecture of IoT

Applications of IoT

Understanding the capabilities of ESP32 for IoT

A brief overview of the ESP32 board and its variants

ESP32 versus other development boards

Deep dive into the Arduino IDE 2.0 to program ESP32

How can ESP32 be programmed?

The Arduino IDE 2.0

Installing the Arduino IDE 2.0

An overview of the Arduino IDE 2.0 user interface

Setting up the Arduino IDE 2.0 for ESP32

ESP32 Hello World example using the Arduino IDE 2.0

Bonus – Simulating ESP32 projects

Summary

2

Connecting Sensors and Actuators with ESP32

Technical requirements

Getting hands-on with ESP32 GPIO pins and an overview of them

ESP32 peripherals

ESP32 basic input/output example

ESP32 PWM example

Mastering UART communication

How the UART protocol works

UART communication between two ESP32s

Sensors that use UART communication

I2C communication with ESP32

How I2C communication works

An I2C communication example using ESP32

Devices that use I2C communication with ESP32

Understanding SPI communication

How does SPI communication work

SPI communication example using ESP32

Devices that use SPI communication

Summary

3

Interfacing Cameras and Displays with ESP32

Technical requirements

Using the ESP32 camera module

How to use ESP32-CAM with the Arduino IDE

ESP32 camera example

Interfacing displays with ESP32

Interfacing a 16x2 LCD with ESP32 using I2C

Interfacing an OLED with ESP32 using I2C

Interfacing a TFT display with ESP32 using SPI and I2C

Interfacing an e-paper display with ESP32

Comparison of displays

Summary

Part 2 – IoT Protocols and ESP32

4

Implementing Network-Based Protocols with ESP32

Technical requirements

Types of networks

Exploring wireless capabilities with Wi-Fi

How the Wi-Fi protocol works

ESP32 built-in Wi-Fi capabilities

Using Wi-Fi Direct for P2P connections

Creating a personal area network with BLE

How the BLE protocol works

ESP32 BLE capabilities

BLE server and client using ESP32

ESP32 as BLE Beacon advertiser

Expanding ESP32 connectivity beyond Wi-Fi and BLE

Cellular communication with ESP32

The LoRaWAN protocol

Comparison of protocols

Summary

5

Choosing the Right Data-Based Protocols for Your ESP32 Projects

Technical requirements

Exploring HTTP with ESP32 – enabling IoT devices to communicate with web servers

What is HTTP?

How does HTTP work?

ESP32 as an HTTP web server

ESP32 as an HTTP client

Configuring and managing Wi-Fi using the HTTP protocol in ESP32

Exploring MQTT for IoT communication with ESP32

What is MQTT?

How does MQTT work?

MQTT pub-sub example

Adding real-time notifications using webhooks

What are webhooks and how do they work?

Webhook example

A real-life analogy of HTTP, MQTT, and webhooks

Comparing HTTP, webhooks, and MQTT

Summary

Part 3 – Practical Implementation

6

Project 1 – Smart Plant Monitoring System Using ESP32, Messaging Services, and the Twitter API

Technical requirements

Interfacing sensors with ESP32

Connecting the sensors

Reading the sensor data

Sending emails using SMTP

Setting up a Gmail account to send emails using ESP32

Writing code for sending emails using ESP32

Using the CallMeBot API to send WhatsApp and Telegram messages

Setting up WhatsApp messages

Setting up Telegram messages

The ESP32 code to send messages on WhatsApp and Telegram

Publishing update tweets on Twitter

Setting up the Twitter API

Code for publishing the plant updates on X/Twitter

Summary

7

Project 2 – Rent Out Your Parking Space

Technical requirements

Interfacing sensors with ESP32

The connection diagram

Reading the distance using the ultrasonic sensor

Reading the push button and controlling the Servo motor

Showing a QR code on the OLED

Integrating the PayPal API

Receiving PayPal notifications in ESP32

Creating a user-friendly experience for potential renters

Real-world implementation and project limitations

Current project limitations

Security concepts in IoT

Summary

8

Project 3 – Logging, Monitoring, and Controlling using ESP32

Technical requirements

Interfacing sensors and actuators with ESP32

Connection diagram

Reading the sensor data

Setting up InfluxDB Cloud and logging the data

Cloud database setup

Logging data to InfluxDB

Monitoring and visualization using the Grafana cloud

Creating a dashboard and visualizing the data

Controlling the main entrance gate using the MQTT protocol

Summary

9

From Arduino IDE to Advanced IoT Development – Taking the Next Steps

Power of ESP-IDF

What is ESP-IDF?

ESP-IDF versus the Arduino ESP32 core

Understanding RTOS use cases and features

FreeRTOS

FreeRTOS example using the Arduino IDE

PlatformIO – an alternative to the Arduino IDE

Using PlatformIO to upload code to ESP32

Enterprise clouds

AWS IoT services

Azure IoT services

A complete IoT embedded and software roadmap

Roadmap for IoT embedded development

Roadmap for IoT applications development

IoT protocols

Message brokers

Databases

IoT platforms

IoT cloud providers

Summary

Index

Other Books You May Enjoy

Preface

The ESP32 is a great microcontroller for learning and creating Internet of Things (IoT) applications. It’s especially good for beginners in the IoT world. Setting up and connecting sensors to the ESP32 can be complicated, but the Arduino IDE makes it easier to write code, upload it to the ESP32, and use its features. This book is designed to help you understand the basics of using sensors, connecting to networks, processing data, and creating applications with the ESP32, giving you a solid foundation for IoT development.

Starting with the basics of the ESP32 and the Arduino IDE 2.0, you’ll learn how to connect sensors to the ESP32 through practical examples. Then, the book shows you how to use the ESP32 camera and display modules with examples. It also explains IoT networks and data protocols, providing you with different options for various IoT applications. Toward the end of the book, you’ll use your knowledge to work on exciting projects, from smart connected devices to data loggers and automation, experiencing real-world applications.

By the end of the book, you’ll be able to confidently work on ESP32 projects, choose the right IoT protocol for your application, and successfully create and deploy your own IoT projects.

Who this book is for

This book is for people who like electronics and IoT, whether you’re just a fan, enjoy it as a hobby, or work in the field. It’s written to help you really understand ESP32 and IoT protocols by giving you practical examples. You should know a bit about electronics and have some experience with programming, but it’s designed to be easy for beginners. So, if you’re interested in learning about ESP32 and IoT, this book is a good choice for you.

What this book covers

Chapter 1

, IoT with ESP32 using Arduino IDE, begins with an introduction to IoT, outlining its characteristics and various applications. Following that, the ESP32 is introduced, and its capabilities are explored in detail. The chapter concludes by explaining and utilizing the Arduino IDE for a Hello World example.

Chapter 2

, Connecting Sensors and Actuators with ESP32, provides an overview of the ESP32’s General Purpose Input/Output (GPIO) and peripherals. The chapter also explores communication protocols used to connect different sensors, including examples of UART, I2C, and SPI.

Chapter 3

, Interfacing Cameras and Displays with ESP32, offers both theoretical insights and practical guidance on utilizing the ESP32-CAM board, along with various display modules in conjunction with the ESP32.

Chapter 4

, Implementing Network-Based Protocols with ESP32, provides an overview of network-based protocols such as Wi-Fi, Bluetooth Low Energy (BLE), Cellular (5G and NB-IoT), and LoRaWAN. The chapter also explores the distinctions between these protocols, offering insights to help you select the most suitable network protocol for your upcoming projects.

Chapter 5

, Choosing the Right Data-Based Protocols for Your ESP32 Project, explores various data-based protocols such as HTTP, MQTT, and webhooks. The chapter outlines the differences between these protocols, aiding you in selecting the most appropriate data-based protocol for your ESP32 projects.

Chapter 6

, Project 1 – Smart Plant Monitoring System Using ESP32, Messaging Services, and the Twitter API, offers a step-by-step guide to reading environmental parameters such as temperature, humidity, and soil moisture using ESP32. Additionally, the chapter covers how to share these status updates on Twitter, Email, WhatsApp, and Telegram using ESP32.

Chapter 7

, Project 2 – Rent Out Your Parking Space, provides a step-by-step guide to creating a prototype system. This system enables you to accept payments via PayPal to rent out your parking space.

Chapter 8

, Project 3 – Logging, Monitoring, and Controlling Using ESP32, outlines a step-by-step approach to reading data from various sensors in different locations within a house, such as the kitchen and bedroom, using ESP32. Moreover, the chapter covers how to log this data in a database, visualize and monitor it, and control components using your smartphone.

Chapter 9

, From Arduino IDE to Advanced IoT Development – Taking the Next Steps, offers a roadmap to advance your IoT development skills and suggests the next steps you can take to build on the knowledge gained from this book.

To get the most out of this book

This book is designed for beginners, so you only need a little knowledge about electronics and programming. To work on the projects in the book, you’ll also need some devices listed in the following table. For the software part, you’ll need the Arduino IDE, which works on all major operating systems. Additionally, the book mentions some free third-party services in different chapters, such as the OpenWeatherMap API, Twitter API, CallMeBot API, InfluxDB, Grafana, and PayPal API.

If you are using the digital version of this book, we advise you to type the code yourself or access the code from the book’s GitHub repository (a link is available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.

The specific uses of both software and hardware are thoroughly explained in their respective chapters with detailed instructions.

Download the example code files

You can download the example code files for this book from GitHub at https://github.com/PacktPublishing/Programming-ESP32-with-Arduino-IDE

. If there’s an update to the code, it will be updated in the GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/

. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: The WiFi.softAP() function is used to set up the ESP32 as an access point.

A block of code is set as follows:

#include

const char* ssid = MyESP32AP;

const char* password = password123;

void setup() {

  Serial.begin(115200);

  WiFi.softAP(ssid, password);

  IPAddress apIP(192, 168, 4, 1);

  IPAddress subnet(255, 255, 255, 0);

  WiFi.softAPConfig(apIP, apIP, subnet);

  Serial.print(Access Point IP Address: );

  Serial.println(WiFi.softAPIP());

}

void loop() {

  // Your code goes here

}

Bold: Indicates a new term, an important word, or words that you see on screen. For instance, words in menus or dialog boxes appear in bold. Here is an example: Now, you can upload the code using Arduino IDE and open Serial Monitor.

Tips or important notes

Appear like this.

Get in touch

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Part 1 – Introduction: Getting Familiar with ESP32

In this section, you’ll familiarize yourself with the fundamental elements of this book, including ESP32, the Internet of Things (IoT), and the Arduino IDE 2.0. Additionally, you’ll learn the utilization and integration of sensors, actuators, cameras, and displays with ESP32 and the Arduino IDE. By the end of this part, you’ll have acquired the necessary hardware-interfacing knowledge, enabling you to move on to exciting IoT projects.

This part has the following chapters:

Chapter 1

, IoT with ESP32 using Arduino IDE

Chapter 2

, Connecting Sensors