Carmine Noviello - Mastering STM32: A step-by-step guide to the most complete ARM Cortex-M platform, using the official STM32Cube, 2nd Edition

It was the summer of 2015 when I began to consider the hypothesis of grouping a series of posts on my personal blog to give shape to a more structured guide about the use of STM32 microcontrollers. At that time, it was not trivial to setup a complete tool-chain for the STM32 portfolio, unless you could afford a license for the ARM Keil. Moreover, STM was migrating from the historical Standard Peripheral Library (SPL) to the new CubeHAL SDK, and it was not clear the path to follow to start learning this very interesting product lineup.

I so started writing the very first chapters of this book, showing how-to setup a complete and free Eclipse tool-chain based on the GNU MCU Eclipse plug-ins by Liviu Ionescu (now called Eclipse Embedded CDT and officially supported by the Eclipse Foundation), and I decided to use the LeanPub platform, which allowed me to publish an in-progress book that I could update as soon as I added a new chapter. From the very first release of the book, many people adopted the text and helped me a lot in shaping the book structure and its contents. It took me two years to complete the first edition and, trust me, it was a very hard work especially because things changed day-by-day. During the years, the book has been adopted by several Universities around the world as official text in Embedded System classes. A lot of people contacted me to provide feedback, some asking for help with the text and some others with the development of their board, some asking for a revision of the text and some others for a revision of the examples, some criticizing the whole book and some other letting me know that they thank me every time they go to sleep.

Seven years later things have changed. A lot. STM pushed hard the development of both the hardware and software ecosystem. The first release of the book was about nine STM32 families, ranging on about 500 P/N. Now there are seventeen families in the STM32 portfolio, spreading over more than 1200 P/N. But the huge improvement was on the software part. STM decided to fix the main issue with the STM32 portfolio: the lack of an official tool-chain. STM acquired Atollic and its TrueStudio IDE, and launched the STM32CubeIDE that, together with the whole STM32Cube initiative, represents a quantum leap for the development of STM32-based devices.

This required me to make a deep revision of the text. I so started working on this second edition in the spring of 2021 and it took to me about one year to update the text and to add new contents that lacked in the first edition. This is a lot of time but things changed a lot even for me in these years. A totally different job, full of too many responsibilities, and a daughter came in the middle, and now my free time ranges from the 5:00am to 7:00am, and you can figure out how hard is to work to a book with 900 pages in just two hours a day.

Even in the second edition, the book is divided in three parts: an introductory part showing how to setup the STM32CubeIDE and how to work with it; a part that introduces the basics of STM32 programming and the main aspects of the official HAL (Hardware Abstraction Layer); a more advanced section covering aspects such as the use of a Real Time Operating Systems, the boot sequence and the memory layout of an STM32 application, advanced peripherals like the USB.

However, this book does not aim to replace official datasheets from ST Microelectronics. A datasheet is still the main reference about electronic devices, and it is impossible (as well as making little sense) to arrange the content of tens of datasheets in a book. You have to consider that the official datasheet of the one of latest - and not the most complex of the portfolio - STM32G4 MCU alone is almost three thousand pages! Hence, this text will offer a hint to start diving inside the official documentation from ST. Moreover, this book will not focus on low-level topics and questions related to the hardware, leaving this hard work to datasheets. Lastly, this book is not a cookbook about custom and funny projects: you will find several good tutorials on the web.

This book is addressed to novices of the STM32 platform, interested in learning in less time how to program these fantastic microcontrollers. However, this book is not for people completely new to the C language or embedded programming. I assume you have a decent knowledge of C and are not new to most fundamental concepts of digital electronics and MCU programming. The perfect reader of this book may be both a hobbyist or a student who is familiar with the Arduino platform and wants to learn a more powerful and comprehensive architecture, or a professional in charge of working with an MCU he/she does not know yet.

I received this question many times from several people in doubt about which MCU platform to learn. The answer is not simple, for several reasons.

First of all, Arduino is not a given MCU family or a silicon manufacturer. Arduino is both a brand and an ecosystem. Today, there are tens of Arduino development boards available on the market, some with am 8-bit MCU and some other with more powerful 32-bit MCUs, even if it is common to refer to the Arduino UNO board as the Arduino. Arduino UNO is a development board built around the ATMega328, an 8-bit microcontroller designed by Atmel. However, Arduino is not only a cold piece of hardware but it is also a community built around the Arduino IDE (a derived version of Processing) and the Arduino libraries, which greatly simplify the development process on ATMega MCUs. This large, stable and continuously growing community has developed hundreds of libraries to interface as many hardware devices, and thousands of examples and applications.

So, the question is: Is Arduino good for professional applications or for those wanting to develop the last mainstream product on Kickstarter?. The answer is: YES, definitively.. I myself have developed a couple of custom boards for a customer, and being these boards based on the ATMega328 IC (the SMD version), the firmware was developed using the Arduino IDE. So, it is not true that Arduino is only for hobbyists and students.

However, if you are looking for something more powerful than an 8-bit MCU or if you want to increase your knowledge about firmware programming (the Arduino environment hides too much detail about whats under the hood), the STM32 is probably the best choice for you. Thanks to a development environment based on Eclipse and GCC, you will not have to invest a fortune to start developing STM32 applications. Moreover, if you are building a cost sensitive device, where each PCB square inch makes a difference for you, consider that the STM32F0 value line is also known as the