Getting started with STM: STM32L4R9 Discovery

STM32L4R9 Discovery board (STM32L4R9I-DISCO).

The following article explains all necessary steps to create an Embedded Wizard UI application suitable for the STM32L4R9 Discovery board. Please follow these instructions carefully and step by step in order to ensure that you will get everything up and running on your target. Moreover, this article assumes, that you are familiar with the basic concepts of Embedded Wizard.

Prerequisites

First of all, you need the following hardware components:

STM32L4R9 Discovery board from STMicroelectronics (STM32L4R9I-DISCO)

USB cable to connect the board with your PC

Make sure that you have got the following software packages:

Embedded Wizard Studio Free or Embedded Wizard Studio Pro

Embedded Wizard STM32 Platform Package

Embedded Wizard Build Environment for STM32L4R9 Discovery

TIP

If you want to use the Free edition of Embedded Wizard Studio and the STM32 Platform Package, please register on our website and select the target STM32L4R9 Discovery. Then you can download the above software packages.

All customers who licensed Embedded Wizard can visit our download center to get the above software packages.

Installing Tools and Software

Step 1: Install the latest version of Embedded Wizard Studio.

Step 2: Install the Embedded Wizard STM32 Platform Package.

Step 3: Download the STM32 ST-LINK utility and install it. Test the connection from PC to Discovery board and the proper installation of the USB drivers: Connect the Discovery board with your PC via USB (make sure to use the ST-LINK USB connector) and start the previously installed STM32 ST-LINK utility. Select the menu item TargetConnect and verify that the connection could be established successfully. Finally, close the STM32 ST-LINK utility.

Step 4: Unpack the provided Embedded Wizard Build Environment for STM32L4R9 Discovery to your local file system (e.g. C:\STM32\STM32L4R9-Discovery).

Step 5: Take a text editor and open the file StartGccBuildEnvironment.bat that you will find in the root directory of the Build Environment. At the beginning of the file, the following environment variable has to be set to the installation path of the ST-LINK utility:

ST-LINK_Utility_Path - Absolute path of your installed STM32 ST-LINK utility (Step 3).

Exploring the Build Environment

The provided Embedded Wizard Build Environment for STM32L4R9 Discovery contains everything you need to create, compile, link and flash an Embedded Wizard UI application for the STM32L4R9 target. After unpacking, you will find the following subdirectories and files:

StartGccBuildEnvironment.bat - This script file is provided to start a windows command line to build your GUI applications for the target. Don't forget to set the path of your installed ST-LINK utility.

\Application - This folder contains ready-to-use projects to compile and link an Embedded Wizard generated UI application. They are used for all provided examples and they can be used to build your own UI applications.

\GeneratedCode - This folder is used to receive the generated code from an Embedded Wizard UI project. All template projects are building the UI application out of this folder. You can create your own UI project and generate the code into the subdirectory \GeneratedCode without the need to adapt the project.

\Project - This folder contains the prepared projects for GCC (make), IAR Embedded Workbench, Keil MDK-ARM and Atollic TrueSTUDIO.

\Source - This folder contains the files main.c and ewmain.c. There you will find the initialization of the system and the main loop to drive an Embedded Wizard GUI application. Additionally, this folder contains a configuration file for FreeRTOS and the device driver C/H files used for the DeviceIntegration example.

\Examples - This folder contains a set of demo applications. Each example is stored in a separate folder containing the entire Embedded Wizard UI project. Every project contains the necessary profile settings for the STM32L4R9 target. The following samples are provided:

\HelloWorld - A very simple project that is useful as starting point and to verify that the entire toolchain, your installation and your board is properly working.

\ColorFormats - This project demonstrates that every UI application can be generated for different color formats: RGBA8888, RGB888, RGB565, Index8 and LumA44.

\ScreenOrientation - This demo shows, that the orientation of the UI application is independent from the physical orientation of the display.

\DeviceIntegration - This example shows the integration of devices into a UI application and addresses typical questions: How to start a certain action on the target? How to get data from a device?

\GraphicsAccelerator - This application demonstrates the graphics performance of the DMA2D hardware graphics accelerator. Sets of basic drawing operations are executed permanently and continuously, while the user can switch on/off the hardware accelerator.

\AnalogWatches - This application contains a set of analog watches with rotating clock hands.

\BrickGame - The sample application BrickGame implements a classic "paddle and ball" game. In the game, a couple of brick rows are arranged in the upper part of the screen. A ball travels across the screen, bouncing off the top and side walls of the screen. When a brick is hit, the ball bounces away and the brick is destroyed. The player has a movable paddle to bounce the ball upward, keeping it in play.

\PlatformPackage - This folder contains the necessary source codes and/or libraries of the STM32 Platform Package: Several Graphics Engines for the different color formats (RGBA8888, RGB888, RGB565, Index8 and LumA44) and the Runtime Environment (in the subdirectory \RTE).

\TargetSpecific - This folder contains all configuration files and platform specific source codes. The different ew_bsp_xxx files implement the bridge between the Embedded Wizard UI application and the underlying board support package (STM32 hardware drivers) in order to access the display, the graphics accelerator, the serial interface and the clock.

\ThirdParty - This folder contains third-party source codes and tools:

\gcc-arm-none-eabi - This folder contains a subset of the GCC ARM embedded toolchain to compile the examples.

\Make - This folder contains a make tool to build the entire GUI application via command line.

\STM32Cube_FW_L4 - This folder contains the necessary subset of the STM32CubeL4 embedded software for STM32L4 series used for the Embedded Wizard UI applications (HAL, BSP, drivers, FreeRTOS).

\TLSF - This folder contains the memory manager used for the Embedded Wizard UI applications.

\Xprintf - This folder contains a helper module for printing debug messages.

Creating the UI Examples

For the first bring up of your system, we recommend to use the example 'HelloWorld':

Example 'HelloWorld' within Embedded Wizard Studio.

The following steps are necessary to generate the source code of this sample application:

Navigate to the directory \Example\HelloWorld.

Open the project file HelloWorld.ewp with your previously installed Embedded Wizard Studio. The entire project is well documented inline. You can run the UI application within the Prototyper by pressing Ctrl+F5.

To start the code generator, select the menu items BuildBuild this profile - or simply press F8. Embedded Wizard Studio generates now the sources files of the example project into the directory \Application\GeneratedCode.

Compiling, Linking and Flashing

The following steps are necessary to build and flash the Embedded Wizard UI sample application using the GCC ARM embedded toolchain:

Navigate to the top level of the Build Environment.

Open StartGccBuildEnvironment.bat - as a result, a windows command line window should open. In case there are error messages, please edit the file and double-check the path settings.

Now start compiling, linking and flashing:

make
make install

If everything works as expected, the application should be built and flashed to the STM32L4R9 target.

Example 'HelloWorld' running on STM32L4R9 Discovery board.

All other examples can be created in the same way: Just open the desired example with Embedded Wizard Studio, generate code and rebuild the whole application using simply:

make install

Creating your own UI Applications

In order to create your own UI project suitable for the STM32L4R9 target, you can create a new project and select the STM32L4R9 Discovery project template:

As a result you get a new Embedded Wizard project, that contains the necessary Profile attributes suitable for the STM32L4R9 Discovery board:

The following profile settings are important for your target:

The attribute PlatformPackage should refer to an installed STM32 Platform Package. Please note, that for STM32L4R9 only the color formats RGBA8888, RGB888, RGB565, Index8 or LumA44 can be used.

The attribute ScreenSize should correspond to the display size of the STM32L4R9 Discovery board.

The attributes FormatOfBitmapResources and FormatOfStringConstants should be set to DirectAccess. This ensures that the resources are taken directly from flash memory.

The attribute OutputDirectory should refer to the \Application\GeneratedCode directory within your Build Environment. By using this template, it will be very easy to build the UI project for your target.

The attribute CleanOutputDirectories should be set to true to ensure that unused source code within the output directory \Application\GeneratedCode will be deleted.

The attribute PostProcess should refer to \Application\Project\EWARM\EWARM_ew_post_process.cmd if you are working with IAR Embedded Workbench or to \Application\Project\MDK-ARM\MDK-ARM_ew_post_process.cmd if you are working with Keil MDK-ARM or to \Application\Project\TrueSTUDIO\STM32L4R9-Discovery\TrueSTUDIO_ew_post_process.cmd if you are working with Atollic TrueSTUDIO. In case of the GCC ARM embedded toolchain leave it blank

Now you can use the template project in the same manner as it was used for the provided examples to compile, link and flash the binary.

After generating code, please follow these steps, in order to build your own UI application:

Start the batch file 'StartGccBuildEnvironment.bat'. Again, a windows command line window should open.

Start compiling, linking and flashing:

make install

Most of the project settings are taken directly out of the generated code, like the color format or the screen orientation. Only a few additional settings can be configured directly within the Makefile, like the usage of an external flash memory or the usage of the FreeRTOS operating system.

Console output

In order to receive error messages or to display simple debug or trace messages from your Embedded Wizard UI application, a serial terminal like 'Putty' or 'TeraTerm' should be used.

As soon as you connect your STM32L4R9 target with the PC via USB, a STMicroelectronics STLink Virtual COM Port (COMx) appears within your system device list. Open the device manager to get the number of the installed COM port.

Now you can open your terminal application and connect it via COMx with the following settings: 115200-8-N-1

This terminal connection can be used for all trace statements from your Embedded Wizard UI applications or for all debug messages from your C code.

Using IAR Embedded Workbench

If you want to use the IAR Embedded Workbench instead of the GCC ARM embedded toolchain, please follow these instructions:

The subdirectory \Application\Project\EWARM contains a template project that is commonly used for all provided Embedded Wizard examples. All Embedded Wizard examples will store the generated code within the common /Application/GeneratedCode folder.

The generated code of an Embedded Wizard example is imported automatically to the IAR Embedded Workbench project using the Project Connection mechanism.

To establish this automatic project import a post process has to be added to the Profile settings within Embedded Wizard Studio:

Open the desired Embedded Wizard example project.

Select the Profile and set the attribute PostProcess to the file ..\..\Application\Project\EWARM\EWARM_ew_post_process.cmd.

After the Embedded Wizard code generation the installed post process will generate a ewfiles.ipcf file, that controls the import to the IAR Embedded Workbench project.

After returning to IAR Embedded Workbench, the latest generated code and the suitable Embedded Wizard Platform Package will be imported to the IAR Embedded Workbench project (depending on the color format and the screen orientation selected in the Embedded Wizard Profile).

If the color format or the screen orientation was changed, please do a complete rebuild of the IAR Embedded Workbench project.

Using Keil MDK-ARM

If you want to use the Keil MDK-ARM toolchain instead of the GCC ARM embedded toolchain, please follow these instructions:

The subdirectory \Application\Project\MDK-ARM contains a template project that is commonly used for all provided Embedded Wizard examples. All Embedded Wizard examples will store the generated code within the common /Application/GeneratedCode folder.

The generated code of an Embedded Wizard example is imported automatically to the Keil MDK-ARM project using the CMSIS PACK mechanism.

The following steps are needed to establish this automatic project import:

Install Tara.Embedded_Wizard_Launcher.x.x.x.pack by double clicking. You will find the file within the subdirectory \Application\Project\MDK-ARM.

Open the desired Embedded Wizard example project.

Select the Profile and set the attribute PostProcess to the file ..\..\Application\Project\MDK-ARM\MDK-ARM_ew_post_process.cmd.

After the Embedded Wizard code generation the installed post process will generate a ewfiles.gpdsc file, that controls the Keil MDK-ARM project import.

In Keil MDK-ARM a dialog appears: "For the current project new generated code is available for import". After confirmation, the latest generated code and the suitable Embedded Wizard Platform Package will be imported to the Keil MDK-ARM project (depending on the color format and the screen orientation selected in the Embedded Wizard Profile).

If the color format or the screen orientation was changed, please do a complete rebuild of the Keil MDK-ARM project.

Using Atollic TrueSTUDIO

If you want to use the Atollic TrueSTUDIO toolchain instead of the GCC ARM embedded toolchain, please follow these instructions:

The subdirectory \Application\Project\TrueSTUDIO contains a template project that is commonly used for all provided Embedded Wizard examples. All Embedded Wizard examples will store the generated code within the common /Application/GeneratedCode folder.

The following steps are needed to establish this automatic project import:

Open the desired Embedded Wizard example project.

Select the Profile and set the attribute PostProcess to the file ..\..\Application\Project\TrueSTUDIO\STM32L4R9-Discovery\TrueSTUDIO_ew_post_process.cmd.

After the Embedded Wizard code generation the installed post process will adapt the .cproject XML file. All necessary libraries and include paths (depending on the color format and screen rotation) will be set automatically.

The given TrueSTUDIO example under \Application\TrueSTUDIO contains a workspace which has all adaptions for an Embedded Wizard project. For using this within Atollic TrueSTUDIO do following steps:

Open Atollic TrueSTUDIO and select the directory \Application\Project\TrueSTUDIO as workspace directory.

To import the C project, select the menu item File - Import and choose General - Existing Projects into Workspace and press Next.

Choose Select root directory - Browse and select the directory \Application\Project\TrueSTUDIO\STM32L4R9-Discovery.

Press Finish.

To compile the project select Project - Build Project.

Choose a Run or Debug Configuration under Run - Debug History.

If the color format or the screen orientation was changed, please do a clean in Atollic TrueSTUDIO.

Custom specific hardware

In order to bring-up an Embedded Wizard generated UI application on your STM32 custom hardware, you can use the provided Embedded Wizard Build Environment for STM32L4R9 Discovery as a template. The subdirectory \TargetSpecific contains all configuration files and platform specific source codes. Assuming that your custom hardware is similar to the STM32L4R9 Discovery board, the following adaptations or configurations are typically necessary:

System clock (ew_bsp_system.c) - The first and the important step is to configure the system and peripheral clock. Depending on your hardware you can use the internal or external clock as source. Please take care that your LTDC and USART are connected to the selected clock source and configured correctly. The Embedded Wizard UI application runs independent from the chosen system frequency, however, with a slow system clock, all components need more time for their tasks (e.g. display refresh).

USART (ew_bsp_serial.c) - Typically, the USART configuration just requires a new pinout according your hardware layout. The usage of the serial connection is highly recommended in order to get status and debug messages during runtime.

LTDC and DSI (ew_bsp_display.c) - The LTDC is an integrate display controller which allows you to connect many different display types to a STM32 device. In case of STM32L4R9 Discovery, the MIPI-DSI is used as interface to the display. In case you are not using a MIPI-DSI display, please use the Build Environment for STM32F407-Discovery as template.

Touch (ew_bsp_touch.c) - If your application requires touch support, you can integrate a given touch driver provided by the touch controller manufacturer or write your own. As a result the current touch position should be returned.

As soon as these steps are done, you can create your own GUI application or use one of the provided examples. If the size of your display is different compared to the display of the STM32L4R9 Discovery board (390x390 pixel), please adapt the attribute ScreenSize of the UI project and the size of the framebuffer within the file ewmain.c accordingly.