Advanced Embedded Software with STM32, FreeRTOS & Modbus

Develop Real-World Embedded Software Skills with STM32 Using CMSIS, FreeRTOS & Modbus with an Air Quality Sensor Project

This course contains the use of artificial intelligence.

(e.g., a Python script used to test the Modbus application). Temporary AI-assisted narration in the final lessons is being replaced with natural voice recordings.

If you’ve already know the basics of STM32 driver development or FreeRTOS, you may be looking for the next step: a way to bring these skills together into a real-world, professional project.

This course is designed exactly for that purpose. You’ll build a complete indoor air quality sensor project from the ground up, using an STM32 Nucleo board, developing and integrating CMSIS-based peripheral drivers, FreeRTOS tasks, and custom Modbus RTU framework into a structured embedded software project.

By working step-by-step through the design and implementation, you’ll not only learn how these elements work individually, but also how to architect, synchronize, and integrate them into a cohesive, real-world application.

About the Course

We begin with the foundation:

• Integrating CMSIS for register-level development.

• Integrating FreeRTOS as our real-time operating system.

• Creating the startup FreeRTOS task.

• Setting up system clocks and a clean project structure.

From there, we build the project incrementally:

• Writing a clean GPIO driver and non-blocking, UART, SPI, and I2C drivers that use FreeRTOS semaphores for synchronization.

• Developing application-level FreeRTOS tasks to handle data acquisition, processing, and communication.

• Adding external hardware: Sensirion environmental sensors (e.g., SHT3x, SGP40) and a custom FRAM driver over SPI for data storage.

• Integrating a custom Modbus RTU framework, and then build the application-level tasks which support communication and data handling.

Each piece is added step by step so you’ll see not just the code, but also the reasoning behind the design choices.

Intended Outcome

By the end of the course, you’ll have:

• A fully functioning Air Quality Sensor project running on an STM32 MCU.

• The ability to write register-level drivers using CMSIS.

• Experience applying FreeRTOS synchronization mechanisms (queues, semaphores, mutexes and task notifications).

• Practical knowledge of Modbus RTU integration and implementation.

• A clear understanding of how to structure and grow professional embedded projects.

This is not about isolated demos. It’s about learning how to build embedded software the way it’s done in real development environments.

Other Noteworthy Highlights

• Professional, modular programming style used throughout.

• I2C, SPI, and UART drivers implemented with FreeRTOS synchronization for non-blocking operation.

• Error Handling, System Health Monitor, Sensor Data Acquisition, Modbus Slave & Modbus Data Manager implemented as FreeRTOS tasks.

• Step-by-step incremental project development.

• Real-world integration of sensors and external memory.

Hardware

• STM32F446RE Nucleo Board (recommended)

  • A large portion of the course can be completed using just this board, so you can get started right away.

  • The external sensors (I2C temperature/humidity & VOC Index) and SPI FRAM can be integrated as you obtain them.

Software

• STM32CubeIDE

• A Modbus master tool (e.g., Simply Modbus Master) for testing communication