How to learn stm32 in basics?

As a veteran who has been in the embedded field for more than ten years, every time I see a question like "0 Basics Learn STM32", I can't help but want to laugh, but I feel helpless. This is like asking "How to learn how to fly a plane in 0 basics" - although it is theoretically feasible, the process is probably not that pleasant. But then again, every embedded engineer has the day that starts from 0, including me now. So today, I will share my experience and experience of growing from a rookie to an architect, hoping to give you some references to those who also want to get started with STM32.

My STM32 Introduction

Let me first talk about my own introductory experience. Ten years ago, I was a college student who was about to graduate and chose a project based on STM32 for graduation design. At that time, I only knew a little C language and had never even touched the word "single" of microcontrollers. It can be said that it is the standard "0 basis".

When I got the first STM32F103 development board, I was completely confused by it: a blue PCB board was densely covered with various components, pins, and a data sheet of dozens of pages was like a heavenly book. The feeling at that time was: Can this thing really be understood by humans?

I tried to follow the online tutorial, but the first step was stuck - how to burn the program into the chip? After a whole day of hard work, the senior came over to help me pick up the downloader, which was considered a solution. Then I lighted up the first LED, a simple task that made me debug for three days. The problem lies in the clock configuration. At that time, I didn’t understand what a clock tree was, so I blindly copied the code, and the result was naturally a failure.

That period was a nightmare: I was wondering about my IQ every day and wondering if I was not suitable for learning this. But after the initial painful period, the situation began to improve. That sense of accomplishment was indescribable when I first succeeded in getting the LED to flash as expected. Since then, I have completely fallen in love with embedded development and it has gone out of control.

After graduation, I joined a company that does industrial control and officially became a STM32 development engineer. The challenges encountered in work are much greater than those in school laboratories: not only to ensure the implementation of functions, but also to consider various factors such as performance, reliability, and power consumption. I have made countless mistakes in this process, but I have also accumulated valuable experience. Looking back now, it was that difficult self-study experience that trained my problem-solving ability and laid the foundation for my later career development.

So, if you are 0-based now and want to learn STM32, what I want to say is: This path is indeed a bit difficult, but it is definitely worth it, and it is completely feasible. As long as the method is correct and persists, you will definitely succeed. Next, I will share what I think is the most effective learning path.

Do you really need to start with STM32? —Suggestions for 0 basic learners

Before talking about the specific learning path, I would like to ask a question first: For you with 0 basics, is STM32 really the best starting point?

I'm not trying to dissuade anyone, but I want to illustrate the fact that the STM32, as a 32-bit ARM microcontroller, has a much steep learning curve compared to an 8-bit microcontroller (such as the AVR used by the Arduino) or a 51 microcontroller. It has more complex internal structures, more registers and peripherals, and a more professional development environment... These are undoubtedly huge challenges for 0 basic learners.

I made the mistake of "ambition-oriented" back then and started directly with STM32, but ended up paying a lot of avoidable pain in the early stage. If I go back in time, I will start with a more friendly platform like Arduino, build the basic concepts and confidence before transitioning to STM32.

Of course, that doesn't mean you have to do it. If you have enough determination and patience, it is also completely feasible to learn STM32 directly. It's just that the path will be steeper and you need to be mentally prepared.

Assuming you have decided to challenge STM32 directly, or you have some programming or electronics foundations, I will introduce a detailed learning path that I think is the most reasonable one. This path is summarized based on my own experience and tutoring for many students. I hope it can help you avoid detours.

Step 1: Consolidate the basic knowledge—Don’t rush to get started with STM32

The biggest mistake many beginners make is that they are too impatient and want to start programming immediately after getting the development board. But without the necessary basic knowledge, such attempts often end in frustration. Before officially touching STM32, it is recommended to master the following basics:

Basics of C language programming

The development of STM32 mainly uses C language, so a solid C language foundation is essential. You don’t need to become a C language expert, but at least you need to understand basic syntax, functions, pointers, structures and other concepts.

I had a poor foundation in C language back then, which led to a lot of difficulties when learning STM32 library functions later. In particular, the understanding of pointers is not in-depth, and it is often confused when debugging hardware registers, which wastes a lot of time.

If your C language foundation is weak, it is recommended to spend 1-2 months to study it systematically. "C Primer Plus" is a good introductory book. During the learning process, focus on concepts often used in microcontroller development, such as pointers, structures, and bit operations.

Digital circuit basics

Microcontrollers are digital chips, and understanding basic knowledge of digital circuits is very helpful in understanding how it works. It is recommended to master the following content:

Binary, hexadecimal notation and conversion
Basic logic gates (Add, or, non) and combinations thereof
Basic digital circuits such as triggers and counters
Basic timing logic concepts

I remember debugging a strange question once: Why do my keys sometimes trigger interrupts, but sometimes they don't? Finally, I found that I lacked the understanding of the concept of "jitter" in digital circuits and did not do key dejittering. This simple digital circuit knowledge point has bothered me for several days.

Basic concepts of microcontrollers

Before getting into specific STM32 chips, it is helpful to understand some common concepts of microcontrollers:

CPU architecture and working principle
Memory type (Flash, RAM, ROM, etc.)
The concept and function of registers
The basic principles of clock system
Interrupt mechanism
Basic working principle of common peripherals (GPIO, UART, SPI, I2C, etc.)

This looks a lot, but it doesn't require a deep understanding of all the details from the beginning. Just have a general concept and gradually deepen your understanding in subsequent practice.

I ignored this step back then and started to read the STM32 information directly. As a result, I often felt confused when I saw it halfway because I didn’t understand too many terms and concepts. Later, I had to come back to make up for these basic knowledge, which wasted a lot of time.

Step 2: Understand ARM and STM32—understand the objects you are about to conquer

After laying the foundation for basic knowledge, the next step is to have a holistic understanding of STM32. Don't rush to write code, first understand the characteristics and architecture of this platform.

Understand the ARM Cortex-M architecture

STM32 is a microcontroller family based on the ARM Cortex-M core. Understanding the basic characteristics of ARM architecture is very helpful for subsequent learning:

ARM's business model (ARM only designs cores and does not produce chips)
Positioning and features of Cortex-M series
The difference between Cortex-M3/M4/M0 and other cores
Features of ARM's instruction set

I remember when I first started studying, I often couldn't figure out the relationship between ARM and STM32, thinking that they were competitive relationships. Later I realized that ARM only designed kernels, while companies such as ST designed complete microcontroller products based on these kernels. This understanding is very helpful for understanding the entire ecosystem.

Get to know the STM32 product series

ST Company has developed multiple series of STM32 products based on the ARM core, targeting different application scenarios. Beginners are often confused by these complex product lines:

Positioning and characteristics of F0/F1/F4/F7/H7 and other series
Different series of performance, resources and applicable scenarios
Naming rules for common models (such as the meaning of each part in STM32F103C8T6)

You don't need to remember all the details, but you need to have a holistic understanding of the product structure of the STM32 and know where the chip you are learning is in the entire series.

When I first studied, I used the STM32F103 series, which is a mid-range product in the F1 series. It has moderate performance and rich resources, which is very suitable for introductory learning. Although this series is not the latest, it is still a good learning platform because of its rich information and low prices.

Familiar with the development ecosystem of STM32

Understanding the development environment, toolchain and resources of STM32 is crucial for subsequent learning:

Common IDEs: Keil MDK, IAR, STM32CubeIDE, etc.
Development Board Selection: Official Evaluation Board vs. Third-party Development Board
Debugging tools: ST-Link, J-Link, etc.
Firmware library: The difference between standard peripheral library (StdPeriph), HAL library, and LL library
Reference materials: Reference manual (RM), Data manual (DS), etc.

I made a lot of mistakes in this area back then. At first I used the pirated Keil, but I encountered some inexplicable problems; later I downloaded the wrong version of the library function, and it took several days to find that the mismatch was not matched. If you know this information in advance, you can avoid many unnecessary troubles.

Step 3: Prepare the development environment—Select the right equipment

With the theoretical foundation, the next step is to prepare for the actual developed hardware and software environment. This step seems simple, but if the choice is not right, you will encounter a lot of trouble in the future.

Choose the right development board

For beginners, it is highly recommended to start with an official or well-known third-party development board instead of designing the circuit yourself:

Official evaluation board (such as NUCLEO series, Discovery series): well-documented, best support, but higher price
Third-party development boards (such as products from domestic manufacturers such as Zhengdian Atoms and Wildfire): Usually equipped with detailed Chinese tutorials, at a reasonable price
Minimum system board (such as "Blue Pill" STM32F103C8T6 minimum system): the lowest price, but no peripherals, you need to connect it yourself

My own experience is that third-party development boards are the most cost-effective choices with corresponding tutorials. I used the STM32F103 development board of the positive atom. It not only has a complete peripheral, but also has detailed Chinese tutorials, which greatly reduces the difficulty of getting started.

If the budget is limited, the "Blue Pill" minimum system board is also a good choice, with a price of about 10-20 yuan, which can meet basic learning needs. But it should be noted that you need to purchase an additional ST-Link downloader and some peripheral modules.

Build a software development environment

Choosing the right IDE (integrated development environment) is very important for beginners:

Keil MDK: The most popular STM32 development environment, the richest information, but the full version is expensive
IAR Embedded Workbench: Powerful, commercial software, high price
STM32CubeIDE: ST official free IDE, based on Eclipse, integrated CubeMX functions
PlatformIO + Visual Studio Code: Open source solution, becoming more and more popular in recent years

I recommend that beginners use STM32CubeIDE, it is completely free, powerful, and officially supported by ST, and there will be no compatibility issues. In addition, it integrates CubeMX graphical configuration tools, which can greatly simplify early development work.

I initially used Keil MDK (and honestly pirated) and did encounter some inexplicable problems. Later, I turned to official tools. Although the interface was not as beautiful as Keil, the stability and consistency were much better.

Prepare debugging tools

Debugging tools are crucial to microcontroller development and can help you find problems in code and hardware:

ST-Link: ST official debugger, affordable, best compatibility with ST chips
J-Link: a debugger with better performance, supports more features, but is priced higher
Logic analyzer: very useful for debugging communication protocols (such as I2C, SPI)
Oscilloscope: A must-have tool for analyzing analog signal and timing problems

For beginners, a ST-Link V2 (prices around 30-50 yuan) is enough. If economic conditions allow, a basic digital oscilloscope will also greatly help you understand hardware behavior.

I remember one time debugging an SPI communication problem, and I couldn't find the reason. Later, I borrowed the senior's logic analyzer and found that the timing was completely wrong. Without these tools, it is difficult to find such problems simply by guessing.

Step 4: Hello World—Let your STM32 say the first sentence

After preparing the environment, you can finally start the actual programming. The first project should always be simple, and building confidence is the most important thing.

Light up the first LED

Almost all microcontroller learning starts with controlling LEDs, and STM32 is no exception. This simple project involves basic operations of GPIO and is a good starting point for understanding how STM32 works.

Specific steps include:

Understand how the LEDs on the development board are connected (which GPIO is connected, whether it is high or low)
Configure GPIO clock and mode
Control the GPIO output status
Add delay to achieve LED flashing

It seems simple, but in this process you will be exposed to multiple basic concepts of STM32: clock tree, AHB/APB bus, GPIO working mode, etc.

I remember the excitement when I first succeeded in making the LED flash, and at that moment I felt like I was the next Tony Stark in the embedded realm! Although I later learned that this was just the most basic operation, that sense of accomplishment was real and it was also the motivation to continue learning.

Use serial port to communicate with computer

After the LED is lit, the next milestone is usually to realize serial communication. This allows your STM32 to "talk" with the computer, greatly facilitating debugging and information display.

This project involves:

Basic configuration of USART peripherals
Implementation of sending and receiving functions
Redirecting printf() function (optional)
Use the serial debugging assistant to view the output

Serial communication seems simple, but in fact it involves many knowledge points: baud rate calculation, USART register configuration, data transmission and reception mechanism, etc. Once you master these, you will have a powerful debugging tool.

During my learning process, once serial communication is realized, the debugging efficiency is immediately improved several times. In the past, the program's running status could only be determined by flashing LEDs. Now, detailed information can be printed directly, and it has become much easier to find problems.

Step 5: Explore the peripheral world of STM32—a step-by-step learning path

After mastering the basics, the next step is to systematically learn various peripherals of STM32. I suggest doing it in an order from easy to difficult:

GPIO advanced: key input, interrupt processing

After mastering LED control, the next step is to learn how to read key input. This may seem simple, but involves some new concepts:

Configuration of input mode (pull up, pull down, float, etc.)
Dejigging (avoiding false triggering caused by key jigging)
Interrupt configuration (EXTI external interrupt)
NVIC Interrupt Controller

Learning interrupt handling is an important milestone, which moves your program from "polling" mode to more efficient "event-driven" mode.

I remember when I first started learning interrupts, I was confused: Why does pressing the key once can sometimes trigger multiple interrupts? Later I learned that this is caused by key jitter, and it needs to be dejittered at the software or hardware level. This kind of practical problems is often the best learning material.

Timer: Accurate time control

The STM32's timer peripherals are powerful and are the core of many applications. Basic applications include:

Timed interrupts (periodically perform certain tasks)
PWM output (control LED brightness, motor speed, etc.)
Input capture (measure pulse width, frequency, etc.)

Timers involve more complex configurations, including prescaler, automatic reload, channel mode and other concepts. But once you master it, you can achieve precise time control and measurement.

When I used PWM to control the LED brightness gradient for the first time, I was shocked by the precise control ability of STM32. Later in a project, I used the input capture function of the timer to measure the echo time of the ultrasonic sensor, achieving the accuracy of distance measurement at the centimeter level.

Communication Protocol: Connecting to the External World

STM32 supports multiple communication protocols, allowing it to interact with various external devices:

UART/USART: Communication with computers, GPS modules, etc.
I2C: Connect to EEPROM, sensor and other devices
SPI: High-speed communication, commonly used in Flash memory, display screen, etc.
CAN: Bus protocol for automotive electronics and industrial control

To learn these protocols, you must not only master the configuration of the STM32 end, but also understand the characteristics and timing requirements of the protocol itself.

In a project, I need to use I2C to read sensor data at the same time, drive the display with SPI, and communicate with the upper computer with UART. The integration of these different protocols is a big challenge, but it also gives me a comprehensive understanding of the communication capabilities of STM32.

ADC and DAC: Bridges to simulate the world

The STM32's ADC (Analog-to-Digital Converter) and DAC (Digital-to-Analog Converter) allow it to interact with the analog world:

ADC: converts analog signals into digital values for reading sensor data
DAC: converts digital values to analog voltages for control or generating signals

This part involves the concepts of sampling rate, resolution, reference voltage, etc., as well as the use of DMA transmission.

I once did a simple oscilloscope project, using ADC to collect signals and then send them to the computer to display via UART. This project combines multiple knowledge points such as ADC, DMA, UART, etc., and is a good comprehensive exercise.

Advanced peripherals: gradually explored as capabilities improve

STM32 also has many advanced peripherals that can be explored gradually as your abilities improve:

RTC: Real-time clock for timekeeping
FSMC/FMC: External memory controller for connecting SRAM, NOR Flash, etc.
USB: Implement USB device or host function
Ethernet: Network connection function

These peripheral configurations are relatively complex and are usually learned after mastering the basic peripherals.

I used the Ethernet function of STM32 in an industrial control project to implement a remote control system based on Modbus TCP. Although the configuration is complex, the power of the STM32 is truly impressive.

Step 6: From library functions to registers—A deep understanding of STM32

As you learn more, you may gradually transition from using library functions to directly manipulating registers. This is an important step to understand the underlying working principle of STM32.

Understand the implementation principle of library functions

Don't simply use library functions as black boxes, but try to understand their implementation principles:

Read the source code of the library function to understand its internal implementation
View the corresponding register definition and bit domain meaning
Try to directly operate registers without using library functions to achieve the same function

This process may be a bit boring, but it can greatly deepen your understanding of STM32.

I remember the first time I tried to directly write registers to control GPIO without using the HAL library, and it felt very novel. Although the amount of code has increased, the execution efficiency has been improved and the sense of control over the hardware has become stronger. This feeling of directly operating the hardware is the unique charm of embedded development.

In-depth study reference manual

The STM32 reference manual is the most authoritative technical document, but it may be obscure for beginners. As you learn more, you should get used to reading these original documents:

Learn more about the working principle of peripherals and register functions
Learning reading methods for timing charts and waveform charts
Pay attention to the precautions and special circumstances in the document

When I was dealing with a complex timer synchronization problem, I searched through the tutorials online but couldn't find the answer. Finally, I found key information in a small comment in the reference manual. This made me understand the importance of the original document—sometimes it only provides the most accurate answer.

Step 7: Project Practice—Integrate knowledge

The ultimate goal of learning is application. Through actual projects, you can connect scattered knowledge points to form a systematic understanding.

Step by step project suggestions

Here are some project suggestions for different stages:

Initial stage:

LED breathing light (PWM control)
Electronic clock (RTC + LCD display)
Temperature and humidity monitoring (sensor + serial port display)

Intermediate stage:

Digital oscilloscope (ADC + DMA + Graphic Display)
Remote control car (motor drive + wireless communication)
Data acquisition system (multiple sensors + storage + communication)

Advanced stage:

Flight Controller (Sensor Fusion + PID Control)
Industrial monitoring system (Ethernet + multi-sensor)
Portable medical equipment (low power design + high reliability)

My first complete project is a smart home controller based on STM32, which integrates temperature and humidity monitoring, relay control, serial communication and other functions. Although the functions are not complicated, the process of integrating these modules gave me a more comprehensive understanding of the STM32 system design.

Learn to debug and troubleshoot problems

Various problems are inevitably encountered during project development, and learning to debug is the key ability:

Print debug information using serial port
Use the debugger to set breakpoints and observe variables
Analyze signal timing using an oscilloscope
Ideas and methods for systematically troubleshooting problems

I remember one time the project suddenly stopped working and I couldn't find the reason after checking it for several days. Finally, I found that a seemingly unrelated code modification caused stack overflow, and the system restarted halfway through the run. This experience made me understand the importance of systematic debugging and not to ignore any possible sources of problems.

Step 8: Continuous Learning—There is no end in the embedded field

Learning STM32 is a continuous process, and even engineers who have worked for many years will continue to learn new knowledge.

Keep the technology updated

The embedded field is developing rapidly, and we must keep our attention to new technologies:

Pay attention to ST's new products and technologies (such as new series such as STM32MP1, STM32WB, etc.)
Learn advanced topics such as RTOS and middleware
Understand emerging application fields such as the Internet of Things and artificial intelligence

After working for a few years, I found that the technology was updated much faster than I thought. The STM32F1 I learned back then was no longer mainstream, and new series such as STM32F4 and STM32H7 brought stronger performance and new features. Continuous learning is the key to staying competitive.

Participate in community and open source projects

If you only study but have no friends, you will be lonely and uninformed. Participating in community exchanges can gain more knowledge and help:

Join STM32 related forums and exchange groups
Read and participate in open source projects
Share your study experience and project experience

I learned a lot of advanced STM32 application skills in an open source flight control project, which are rarely mentioned in the tutorial. Communication with other developers also made me realize my shortcomings and prompted me to continue to improve.

My learning resources recommendations - make your learning work twice as hard as half the effort

Finally, share some resources that I think will be helpful for STM32 learning.

Getting started tutorials and books

"Practical Guide to Development of STM32 Library": A good introductory book in China, based on the standard library
"Mastering STM32": English books, comprehensive introduction to STM32 development
Supporting tutorials for manufacturers such as Zhengdian Atoms and Wildfire Electronics: Usually matched with development boards, suitable for self-study

When I first studied, I mainly relied on tutorials on point atoms, and their pictures and text explanations are very friendly to novices. Later, in order to understand in depth, I read some more professional books and ST original documents.

Video tutorial

There are many free STM32 teaching videos on B station, with uneven quality, so it is recommended to choose one with high clicks.
There are also some paid but systematic embedded development courses on platforms such as Udemy and Coursera.

Video tutorials are helpful for understanding complex concepts. I remember when I was learning DMA, I watched an animation demonstration and instantly understood the working principle of DMA. I couldn’t understand it when I read the text description before.