Advanced UAVs Hardware-In-The-Loop Simulation Platform for STM32-Based Flight Controllers

The reliability of control algorithms for Unmanned Aerial Vehicles (UAVs) is a critical step in the development process, especially when transitioning from simulation to real implementation. Software-In-The-Loop (SITL) methods, though widely used, often fall short of capturing hardware-specific behaviors such as timing constraints and I/O delays. To address this gap, we introduce a Hardware-In-The-Loop (HITL) simulation platform tailored to STM32-based flight controllers. Our system integrates the X-Plane 12 flight simulator with an STM32F4 Discovery board through a lightweight Python middleware that enables real-time, bidirectional communication. The middleware handles sensor emulation, actuator command translation, and precise loop timing, allowing direct testing of control logic on embedded hardware under realistic flight dynamics. Experimental validation confirms the platform’s ability to maintain stable loop frequencies, low communication latency, and accurate response tracking in closed-loop scenarios. This flexible and cost-effective HITL platform offers a valuable framework for researchers and developers to rigorously evaluate both control algorithms and the performance of embedded STM32-based flight controllers under realistic conditions, without the need for physical flight tests. It significantly reduces development risk and time, particularly in academic and prototype-level UAV applications.