1. Create Project

Motivation

In this section we will use STM32CubeMX to generate a working project for a specific MCU. This project will be the basis for the rest of the steps in this how-to guide.

We will refine the project using STM32CubeMX in coming steps and write and integrate code to make all required peripherals work.

This project will be long lived and should be kept. You should now decide on a strategy to keep the different versions available, so that you can go back and run them again. Either on new hardware or just to recheck the hardware.

Maybe you need many small test programs. In that case this project is a good starting point.

Goal

The goal is to create a project in STM32CubeMX that can be flashed to your board and executed. If you have an IDE with a debugger (e.g STM32CubeIDE or IAR Embedded Workbench) you should also check that you can debug and step through your project on the MCU.

If you do not have a debugger you should find a way to print out debug statements from various places in your project. E.g. on a serial port.

Verification

Here are the verification points for this section:

Verification Point	Rationale
Project opens in IDE	The project was generated correctly by STM32CubeMX and can be used as starting point for further board bring up development.
Project compiles	The project is setup correctly with drivers and include paths. We can write more code and recompile the project repeatedly.
Breakpoints are hit	The project can be debugged and stops at breakpoints. We can examine the project state and investigate errors.

Prerequisites

The following are the prerequisites for this step:

STM32 based board
Programming / debugging interface - ST-LINK, JLINK or similar
STM32CubeMX installed
IDE installed - STM32CubeIDE, IAR Embedded Workbench, Keil uVision or similar

Do

We will now go through the steps of creating a new project in STM32CubeMX. In this example we will use the STM32F429 MCU. You should of course select the MCU on your hardware.

In STM32CubeMX click "ACCESS TO MCU SELECTOR" in the "Start My Project from MCU":

Create new Project

It is also possible to start a new project based on a STM32 evaluation kit, e.g. the STM32F429Discovery board. You can/should do this if your hardware design is based on one of the evaluation kits.

We then select the relevant MCU. Here we select the STM32F429ZIT6U:

Select the MCU

Change to the "Project Manager" tab, and give your project a name. You can of course also select a new project location. Under "Application Structure", select Advanced. Under "Toolchain / IDE" you must select your IDE. For this example we select IAR:

Set project name and IDE

Now click the "Generate Code" button in the upper right corner. If this is your first project for the selected MCU family (F4/F7/H7) STM32CubeMX automatically proposes to download the relevant STM32Cube Firmware package. Accept that to get the latest version for later use.

STM32CubeMX can download STM32Cube Firmware

Click "Open Project" to open the project in your IDE:

The project is generated

The project is opened in IAR Embedded Workbench

The project generated by STM32CubeMX contains startup code specific to the MCU, interrupt table, system initialisation code, and HAL drivers for all the peripherals in the MCU.

The project can now be compiled and debugged from your IDE. In IAR we click Project->Make to compile the project, and Project->Download and Debug to debug the project:

Debugging the project in IAR Embedded Workbench

The IAR project is setup to use the STLink debugger. If you are using something else, then change the Debugger properties for the project in your IDE.

The main loop is running continuously

The while loop in main is typically important in projects running without an operating system. Check that you get there by setting a breakpoint and maybe add some code to the loop.

It is recommended to browse the project in your IDE to get familiar with the structure. Try also to step from SystemInit to main.

User Code sections

At this step it is important to understand the concept of "User Code sections" used by STM32CubeMX before you start editing your project. All of the source files in the Core/Src folder in your project are generated by STM32CubeMX. When you later change the project configuration in STM32CubeMX, e.g. to enable a UART, some of these files will be regenerated. You have probably also inserted code in some of these files. Your code will be lost when STM32CubeMX regenerates the project unless you follow one single rule:

Only write code in User Code sections

Any code that you write outside of a User Code section will be deleted by STM32CubeMX.

As an example, let us look at the first few lines in Core/Src/main.c:

main.c

int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */


  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
  ...
}

If you want to insert code here in the beginning of the main function, you must put it between USER CODE BEGIN 1 and USER CODE END 1. If you put code outside this block it will be deleted by STM32CubeMX.

Caution
Do not write code outside User Code sections. Such code will be removed when STM32CubeMX generates code.

1. Create Project

Motivation