Cosmo v1

Abstract

Cosmo FC v1 is a lightweight, modular flight controller architecture designed for autonomous UAVs with a focus on cost-efficiency, reliability, and expandability. At its core lies the STM32H753 microcontroller, which integrates sensor fusion, digital motor control, and real-time telemetry handling. The system features a dual-stack architecture: an FMU (Flight Management Unit) for navigation and control, and a custom 4-in-1 65A ESC for motor driving and power regulation. Sensors such as an IMU, barometer, and current/voltage monitor are directly embedded in the FMU stack, while GPS, LiDAR, and magnetometer are interfaced via dedicated headers. By eliminating separate compute and I/O boards, Cosmo FC v1 achieves a smaller footprint and reduced weight, making it ideal for mid-sized quadcopters requiring autonomous flight capabilities.

Introduction

The Cosmo FC v1 is a compact and efficient flight control system designed for UAVs, addressing the challenges of traditional multi-layer or separate-board controllers by using a two-stack architecture. It separates flight management and sensor fusion (FMU) from motor control (ESC), enhancing modularity and reducing complexity.

The FMU stack centers on the high-performance STM32H753 microcontroller and integrates various sensors, including a 6-axis IMU, barometer, current sensor, magnetometer, GPS, and LiDAR for navigation and precision landing. It controls motors by sending digital DShot600 signals to the ESC stack, which features a custom 4-in-1 ESC powered by an STM32G431 MCU, capable of motor commutation and providing telemetry data back to the FMU.

Power is efficiently managed, supplying the FMU via a regulated 5V line from the ESC board, with onboard voltage regulation for sensors and MCU. Communication interfaces (SPI, I²C, UART) are carefully designed for noise immunity, while the PCB layout emphasizes noise isolation, short trace lengths, decoupling, thermal management, and modularity.

Tested on a 4-motor quadcopter, the Cosmo FC v1 demonstrated stable autonomous flight, accurate altitude hold, reliable telemetry, and effective USB-C configuration, validating its hardware and software design for real-world UAV applications.

Conclusion

Cosmo FC v1 offers a compact and affordable solution for developers, researchers, and hobbyists building autonomous drones. By combining high-performance real-time processing, robust sensor integration, and digital motor control into a 2-stack PCB, it reduces complexity while maximizing functionality. Its design allows for future expansion to include image processing via Raspberry Pi CM5 or UAVCAN-based ESCs. The system is ideal for medium-lift quadcopters, VTOL research platforms, and educational robotics.

References

[1] STMicroelectronics. “STM32H753xI Reference Manual.” [2] Bosch Sensortec. “BMP390 Barometric Pressure Sensor Datasheet.” [3] InvenSense TDK. “ICM-45686 Datasheet.” [4] Texas Instruments. “INA226 Current Shunt Monitor Datasheet.” [5] Benewake. “TF-Luna LiDAR Sensor Datasheet.” [6] u-blox. “NEO-6M GPS Module Specifications.” [7] STMicroelectronics. “STM32G431 Reference Manual.”

Copyright

Copyright © 2025 Achitya Kushwaha. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.