FreeRTOS Embedded Development Learning Library

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<p align="center"> <img src="https://www.freertos.org/fr-content-src/uploads/2018/07/logo-1.jpg" width="400"> </p>

English | 中文

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📚 Project Overview

A comprehensive learning resource for FreeRTOS on STM32 microcontrollers. This repository provides step-by-step tutorials, fully functional example projects, and detailed guides to help you master embedded RTOS development.

Perfect for:

• 🎓 Beginners learning embedded systems
• 🔄 Developers transitioning to RTOS-based applications
• 🛠️ Engineers seeking practical STM32+FreeRTOS examples
• 📝 Students working on academic projects

🌟 Key Features

• 📖 Detailed FreeRTOS porting tutorials from basics to advanced topics
• 🔧 Complete STM32 development environment setup guide with troubleshooting tips
• 💡 Progressive learning path with practical example projects
• 🔄 Real-world demonstrations of RTOS concepts (tasks, queues, semaphores, etc.)
• 📝 Clear documentation in both English and Chinese
• 🔍 Common problem solutions and debugging techniques

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🚀 Quick Start

1. Clone the repository

git clone https://github.com/Despacito0o/FreeRTOS.git
cd FreeRTOS

2. Follow the learning path

This repository is organized as a progressive learning journey, from basics to advanced:

| Level | Project Numbers | Focus | Skills Gained | |-------|----------|-------|--------------| | Beginner | 001-002 | Environment setup, FreeRTOS basics | Development setup, Basic concepts | | Intermediate | 003-006 | Task management, Memory models | Task creation/deletion, Memory optimization | | Advanced | 007-012 | Inter-task communication and synchronization | Parameters, Queues, Semaphores, Resource management |

3. Explore example projects

Each example builds on previous concepts, gradually increasing complexity and functionality:

| Number | Example Project | Description | Key Skills | |-------|----------|-------|--------------| | 001 | STM32 Project Template | Starting point for STM32 development | Standard peripheral library setup | | 002 | FreeRTOS Basic Example | First steps with FreeRTOS | Task creation and execution | | 003 | Dynamic Task Creation | Basics of multitasking | Dynamic memory allocation | | 004 | Static Task Creation | Memory-optimized task creation | Static memory allocation | | 005 | Project Enhancement | Adding UART, debugging capabilities | Peripheral integration & debugging | | 006 | Multi-Task Operations | Creating, deleting, and monitoring tasks | Task lifecycle management | | 007 | Task Parameters | Flexible task functions with parameters | Parameter passing techniques | | 008 | Queue Communication | Basic inter-task communication | Data sharing and transfer | | 009 | Advanced Queue Operations | Efficient data transfer techniques | Structured data transfer | | 010 | Binary Semaphores | Task synchronization and mutual exclusion | Resource protection & synchronization | | 011 | Counting Semaphores | Resource management and event counting | Resource pool management | | 012 | Priority Inversion | Understanding and solving priority inversion | System stability & real-time behavior |

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📋 Project Structure

FreeRTOS/
├── docs/                     # Documentation
│   ├── README.md             # Documentation index
│   ├── en/                   # English documentation
│   │   ├── 001-STM32-Development-Environment-Setup.md
│   │   ├── 002-FreeRTOS-Port-to-Keil6.md
│   │   ├── ...
│   │   └── 012-FreeRTOS-Priority-Inversion-Tutorial.md
│   └── zh/                   # Chinese documentation
│       ├── 001-STM32标准库开发环境搭建教程.md
│       ├── 002-FreeRTOS移植到keil6.md
│       ├── ...
│       └── 012-FreeRTOS优先级翻转详解与实战教程.md
├── Despacito/                # STM32F103 example projects
│   ├── 001/                  # STM32 project template
│   ├── 002/                  # FreeRTOS basic example
│   ├── ...
│   └── 012/                  # FreeRTOS priority inversion example
├── templates/                # Project templates
│   └── README_template.md    # README template for examples
├── CONTRIBUTING.md           # Contribution guidelines
├── CHANGELOG.md              # Version history
├── LICENSE                   # MIT License
└── README.md/README_zh.md    # Project documentation

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📖 Documentation Navigation

📁 Core Documentation

Browse our comprehensive guides following the learning path:

• [001] STM32 Development Environment Setup
• [002] FreeRTOS Port to Keil6
• [003] FreeRTOS Dynamic Task Creation
• [004] FreeRTOS Static Task Creation
• [005] FreeRTOS Project Improvement Guide
• [010] FreeRTOS Binary Semaphore Tutorial (Chinese)
• [011] FreeRTOS Counting Semaphore Tutorial (Chinese)
• [012] FreeRTOS Priority Inversion Tutorial

📝 Project Resources

• Documentation Index - Navigate all available documentation
• Contribution Guidelines - How to contribute to this project
• Change Log - Version history and recent updates

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🔍 Example Projects in Detail

🟢 Beginner Stage (Projects 001-002)

[001] STM32 Project Template

A clean, ready-to-use STM32F103 template with standard peripheral library, providing the foundation for all other examples.

[002] FreeRTOS Basic Example

Your first steps with FreeRTOS - demonstrates basic task creation and simple functionality with LED blinking.

🟠 Intermediate Stage (Projects 003-006)

[003] Dynamic Task Creation

Learn how tasks are dynamically created and scheduled in FreeRTOS, with practical examples of task priorities and scheduling.

[004] Static Task Creation

Explore static memory allocation for task creation - crucial for memory-constrained embedded systems.

[005] Project Enhancement

Take your project to the next level with UART communication, printf debugging, and optimized configurations - making development easier and more productive.

[006] Multi-Task Operations

Master task lifecycle management with dynamic creation and deletion, priority management, and state monitoring techniques.

🔴 Advanced Stage (Projects 007-012)

[007] Task Parameters

Make your tasks flexible and reusable by learning how to pass parameters using void pointers.

[008] Queue Communication

Implement reliable inter-task communication using queues, with examples of both simple message passing and structured data transmission.

[009] Advanced Queue Operations

Explore advanced techniques for efficient data transfer between tasks, including pointer-based methods and solutions for common pitfalls.

[010] Binary Semaphores

Master the use of binary semaphores for task synchronization and mutual exclusion.

[011] Counting Semaphores

Learn to use counting semaphores for resource pool management and event counting, with practical examples for advanced synchronization scenarios.

[012] Priority Inversion

Understand the priority inversion problem in real-time systems, its causes, and how to solve it using priority inheritance and mutexes.

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🤝 Contributing

Your contributions make this resource better for everyone! Please read our Contribution Guidelines before submitting pull requests or issues.

Ways to contribute:

• 📝 Improve documentation and explanations
• 🐛 Fix bugs in example code
• ✨ Add new examples or tutorials
• 🌍 Help with translations
• 💡 Suggest improvements or enhancements

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

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👨‍💻 Author & Contact

• Despacito0o - FreeRTOS developer and tutorial creator
• Visit my CSDN Blog for more embedded development content
• Questions or suggestions? Open an issue or reach out directly!

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🙏 Acknowledgments

• The FreeRTOS development team for their excellent documentation
• STMicroelectronics for their comprehensive peripheral libraries
• All contributors and community members who have improved this resource

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FreeRTOS优先级翻转实战教程：从代码到现象分析

前言

在实时操作系统中，优先级翻转是一个常见但又容易被忽视的问题。本文将通过实际代码演示优先级翻转现象，帮助大家深入理解这一概念。如果你对FreeRTOS有兴趣，可以访问我的完整学习资源：FreeRTOS学习库，从入门到精通的全面指南！

什么是优先级翻转？

优先级翻转是指高优先级任务被低优先级任务间接阻塞的现象。具体场景如下：

• 低优先级任务获取了某个共享资源
• 高优先级任务尝试获取同一资源，但因资源被占用而阻塞
• 中优先级任务此时可以抢占低优先级任务执行
• 结果：中优先级任务先于高优先级任务执行，违背了优先级调度原则

实战演示：创建优先级翻转场景

我们将创建三个任务，优先级依次为：

• Task1：低优先级（优先级2）
• Task2：中优先级（优先级3）
• Task3：高优先级（优先级4）

其中Task1和Task3需要共享同一个二值信号量，而Task2不使用该信号量。

1. 拷贝工程模板

首先，我们基于之前的二值信号量示例（010）创建新工程（012）。

![工程创建](https://i-blog.csdnimg.cn/direc