Author’s Note

An Informatising World

Riding the wave of Internet, Internet of Things (IoT) made its grand debut to become a new type of infrastructure in digital economy. To bring the technology closer to the public, Espressif Systems works for the vision that developers from all walks of life can use IoT to solve some of the most pressing problems of our times. A world of “Intelligent Network of All Things” is what we are expecting from the future.

Designing our own chips makes a critical component of that vision. It is to be a marathon, requiring constant breakthroughs against technological boundaries. From the “Game Changer” ESP8266 to the ESP32 series integrating Wi-Fi and Bluetooth® (LE) connectivity, followed by ESP32-S3 equipped by AI acceleration, Espressif never stops researching and developing products for AIoT solutions. With our open-source software, such as the IoT Development Framework ESP-IDF, Mesh Development Framework ESP-MDF, and Device Connectivity Platform ESP RainMaker, we have created an independent framework for building AIoT applications.

As of July 2022, the cumulative shipments of Espressif’s IoT chipsets have exceeded 800 million, leading in the Wi-Fi MCU market and powering up a huge number of connected devices worldwide. Pursuit for excellence makes every Espressif product a big hit for its high level of integration and cost efficiency. The release of ESP32-C3 marks a significant milestone of Espressif’s self-developed technology. It is a single-core, 32-bit, RISC-V-based MCU with 400KB of SRAM, which can run at 160MHz. It has integrated 2.4 GHz Wi-Fi and Bluetooth 5 (LE) with a long-range support. It strikes a fine balance of power, I/O capabilities, and security, thus offering the optimal cost-effective solution for connected devices. Based on such powerful ESP32-C3, this book is intended to help readers understand IoT-related knowledge with detailed illustration and practical examples.

Why we wrote this book?

Espressif Systems is more than a semiconductor company. It is also an IoT platform company, which always strives for breakthroughs and innovations in the field of technology. At the same time, Espressif has open-sourced and shared its self-developed operating system and software framework with the community, forming a unique ecosystem. Engineers, makers, and technology enthusiasts actively develop new software applications based on Espressif’s products, freely communicate, and share their experience. You can see developers’ fascinating ideas on various platforms all the time, such as YouTube and GitHub. The popularity of Espressif’s products has stimulated an increasing number of authors who have produced over 100 books based on Espressif chipsets, in more than ten languages, including English, Chinese, German, French, and Japanese.

It is the support and trust of community partners that encourages Espressif’s continuous innovation. “We strive to make our chips, operating systems, frameworks, solutions, Cloud, business practices, tools, documentation, writings, ideas, etc., ever more relevant to the answers people need in contemporary life’s most pressing problems. This is Espressif’s highest ambition and moral compass.” said Mr. Teo Swee Ann, Founder and CEO of Espressif.

Espressif values reading and ideas. As the continuous upgrading of IoT technology poses higher requirements on engineers, how can we help more people to quickly master IoT chips, operating systems, software frameworks, application schemes and cloud service products? As the saying goes, it is better to teach a man how to fish than to give him fish. In a brainstorming session, it occurred to us that we could write a book to systematically sort out the key knowledge of IoT development. We hit it off, quickly gathered a group of senior engineers, and combined the experience of the technical team in embedded programming, IoT hardware and software development, all contributing to the publishing of this book. In the process of writing, we tried our best to be objective and fair, stripped of the cocoon, and use concise expressions to tell the complexity and charm of the Internet of Things. We carefully summarised the common questions, referred to the feedback and suggestions of the community, in order to clearly answer the questions encountered in the development process, and provide practical IoT development guidelines for relevant technicians and decision-makers.

This book is officially produced by Espressif Systems and is written by the company’s senior engineers. It is suitable for managers and R&D personnel in IoT-related industries, teachers and students of related majors, and enthusiasts in the field of Internet of Things. We hope that this book can serve as a work manual, a reference, and a bedside book, to be like a good tutor and friend.

While compiling this book, we referred to some relevant research results of experts, scholars, and technicians at home and abroad, and we did our best to cite them according to academic norms. However, it is unavoidable that there should be some omissions, so here we would like to express our deep respect and gratitude to all the relevant authors. In addition, we have quoted information from the Internet, so we would like to thank the original authors and publishers and apologise that we cannot indicate the source of every piece of information.

In order to produce a book of high quality, we have organised rounds of internal discussions, and learned from the suggestions and feedback of trial readers and publisher editors. Here, we would like to thank you again for your help which all contributed to this successful work.

Last, but the most importantly, thanks to everyone at Espressif who has worked so hard for the birth and popularization of our products.

The development of IoT projects involves a wide range of knowledge. Limited to the length of the book, as well as the level and experience of the author, omissions are unavoidable. Therefore, we kindly request that experts and readers criticise and correct our mistakes. If you have any suggestions for this book, please contact us at We look forward to your feedback.