EmberOS

Real-time flight control software enabling autonomous capabilities for the RC MH-EmberEye UAV. Built on STM32F446RE & FreeRTOS with C++ architecture, featuring a Hardware-in-the-Loop (HIL) testing pipeline.

This project is under construction.

Overview

EmberOS is designed as a robust, real-time operating system for autonomous flight control, targeting seamless integration with the MH-EmberEye UAV platform. It leverages advanced sensor fusion, precise control algorithms, and thread-safe state management to ensure reliable performance in dynamic environments. The system aims to support manual control, stabilized flight modes, and full autonomy, with built-in failsafe mechanisms for enhanced safety.

Targeted Features

The project aims to incorporate the following key features:

• Real-Time Operating System: FreeRTOS for efficient multitasking and scheduling, including dedicated tasks for sensor processing, control loops, and status indicators.
• Thread-Safe State Management: RTOS mutexes to protect flight states (e.g., RC commands including roll, pitch, yaw, throttle, and arming status), preventing data races in multi-threaded operations.
• Sensor Fusion: Complementary filter-based processing of MPU6050 accelerometer and gyroscope data for accurate roll and pitch angle estimation.
• High-Frequency Control Loop: Synchronous PID loop operating at 250 Hz (4 ms cycle) for responsive attitude control.
• Custom PID Controller: Advanced PID implementation with anti-windup protection, output saturation limits, and tunable gains (Kp, Ki, Kd) for roll and pitch axes.
• PWM Outputs Layer: Hardware timer-based PWM generation at 50 Hz for servo and motor mixing, enabling precise control of actuators.
• DMA-Based UART Communication Pipeline: Efficient, interrupt-free data transfer for RC receiver integration (e.g., Flysky protocol via UART/PPM), supporting reliable command input.
• Flight Modes and Failsafe: Support for manual and stabilize modes, with failsafe protections for signal loss, including autonomous software layers to handle emergency scenarios.
• Hardware-in-the-Loop (HIL) Testing: Integration with Unity 3D-modeled virtual environments for command and control simulations, allowing safe testing of flight dynamics.
• Autonomous Mission Layers: Progression to full autonomous tasks, building on failsafe autonomy for real-world missions such as waypoint navigation and obstacle avoidance.

Technologies and Components

EmberOS utilizes the following technologies and components:

• Microcontroller: STM32F446RE (ARM Cortex-M4 core) for high-performance embedded processing.
• RTOS: FreeRTOS for real-time task management, semaphores, and mutexes.
• Programming Language: C++ for object-oriented design, including classes for PID controllers, IMU sensors, system management, and status indicators.
• Sensors: MPU6050 IMU connected via I2C for acceleration, gyroscope, and fused attitude data.
• Peripherals and Interfaces: I2C for sensor communication and scanning; UART (with planned DMA support) for debugging, RC receiver input, and serial data pipelines; SPI for potential expansions; GPIO for status LEDs and general I/O.
• Control Algorithms: Custom PID with anti-windup and saturation; complementary filter for sensor fusion.
• Development Tools: STM32Cube HAL library for peripheral initialization (e.g., clock config, GPIO, I2C, UART, SPI); RTOS kernel for thread creation and scheduling.
• Simulation Environment: Unity 3D for HIL testing, enabling virtual world interactions for validation of control and autonomous features.