DESIGN AND DEVELOPMENT OF AN STM32F MICROCONTROLLER-BASED UAV DRONE SYSTEM

Abstract

The increasing deployment of unmanned aerial vehicles (UAVs) in surveillance, inspection, agriculture, logistics, environmental monitoring, and autonomous robotics has intensified the demand for flight-control systems that combine deterministic real-time execution, low hardware cost, and architectural transparency. This paper presents the design, mathematical modeling, embedded implementation, and experimental validation of a custom quadrotor flight controller based on the STM32F411CEU6 32-bit ARM Cortex-M4 microcontroller. Unlike proprietary commercial flight controllers, the proposed platform emphasizes an interpretable embedded architecture in which sensor acquisition, attitude estimation, PID control, motor mixing, communication, and flight-data logging are explicitly implemented and experimentally verified.

 The developed system integrates an MPU6050 inertial measurement unit, BMP280 barometric pressure sensor, QMC5883L three-axis magnetometer, NEO-6M GPS receiver, time-of-flight (ToF) ranging sensor, and W25QXX-series SPI NOR Flash memory. Four 2212 920-kV brushless DC motors driven by electronic speed controllers provide propulsion. A 500-Hz attitude-control loop is implemented using hardware timers, while UART DMA is employed for non-blocking reception of digital radio-control data. Sensor measurements are filtered using low-pass and complementary-filter techniques, after which PID controllers generate roll, pitch, and yaw correction terms. A Quad-X motor-mixing matrix converts these control commands into four ESC pulse-width commands.

 The experimental validation comprises bench-level sensor characterization, oscilloscope-based PWM verification, software debugging using STM32CubeIDE, and tethered flight testing. The measured accelerometer data exhibited substantial vibration-induced disturbance during motor operation; after filtering, the estimated attitude showed substantially reduced variation under stationary conditions. The PWM subsystem generated the required 1000–2000 μs command range with hardware-timer timing. The flight tests demonstrated stable hover and responsive attitude control after empirical PID tuning. The results indicate that an STM32F411-class microcontroller remains a viable platform for deterministic low-cost UAV stabilization when the architecture is carefully designed around bounded computational load, hardware timers, DMA, and appropriately selected sensor-fusion algorithms.