CASE STUDY // SYS-SENSOR-FUSION-UARTHardware Validated PCB
High-Frequency Multi-Sensor Fusion UART Bridge
Custom STM32 embedded platform for synchronous sensor data collection and low-latency UART telemetry distribution.
#EMBEDDED#AVIONICS#ELECTRONICS
DEVELOPMENT YEAR2025
MY ROLEPCB Design, Embedded Firmware & Signal Processing
TEAM STRUCTURESolo Hardware Project
VALIDATION STATUSHardware Validated PCB
THE ENGINEERING PROBLEM
Robotic control units experience telemetry jitter when polling multiple asynchronous sensors (IMU, Barometer, Magnetometer, GPS) on shared buses.
THE ARCHITECTURAL SOLUTION
Designed a dedicated STM32 co-processor board that synchronizes multi-sensor sampling rates and transmits a unified binary stream over high-speed DMA UART.
SYSTEM OVERVIEW & ARCHITECTURE
Custom KiCad 2-layer PCB powered by an STM32 ARM Cortex-M micro-controller running bare-metal C++ firmware with Direct Memory Access (DMA) buffers.
SYSTEM ARCHITECTURE BLOCK DIAGRAM FLOW:
Sensors (MPU6050, QMC5883L, BMP280) → [I2C / SPI] → STM32 (DMA Interrupt Ring Buffer) → [High-Speed UART] → Main Controller.
KEY TECHNICAL HIGHLIGHTS:
- ✓Zero-CPU overhead telemetry streaming using STM32 DMA ring buffers.
- ✓Hardware low-pass RC filtering on sensor power rails for low noise.
HARDWARE & ELECTRONICS
- Custom STM32F4 PCB
- 6-DOF IMU
- Barometric Pressure Sensor
- Magnetometer
- LDO Voltage Regulators
SOFTWARE & FIRMWARE
- Embedded C++
- STM32CubeIDE
- KiCad PCB Layout
- FreeRTOS
ALGORITHMS & CONTROL LOOPS
- Complementary Filter for Attitude Estimation
- DMA Ring Buffer Packet Protocol
- CRC-16 Error Checking
COMMUNICATION PROTOCOLS
- UART DMA
- I2C
- SPI
ENGINEERING CHALLENGES OVERCOME
- Preventing I2C bus lockups during high-frequency sensor interrupt routines.
MY DIRECT CONTRIBUTIONS
- Designed KiCad PCB layout, fabricated prototype, wrote C++ firmware and STM32 DMA drivers.
VALIDATED SYSTEM RESULTS
- ▸Achieved stable 500Hz sensor telemetry streaming with zero dropped packets over 921,600 baud rate UART link.
KEY ENGINEERING LESSONS LEARNED
- ▸Using DMA transfers frees up critical CPU cycles on microcontrollers for complex sensor fusion matrix computations.