CASE STUDY // SYS-CUSTOM-FLIGHT-CONTROLLERHardware Validated Board
Custom STM32 Avionics Flight Controller PCB
Bare-metal STM32-based flight controller hardware and firmware built for high-performance UAV stabilization.
#AVIONICS#EMBEDDED#ELECTRONICS
DEVELOPMENT YEAR2026
MY ROLESchematic Design, PCB Layout, Soldering & Bare-Metal C++ Firmware
TEAM STRUCTURESolo Hardware R&D
VALIDATION STATUSHardware Validated Board
THE ENGINEERING PROBLEM
Commercial flight controllers abstract low-level control loops, limiting deep custom experimentations in attitude control algorithms.
THE ARCHITECTURAL SOLUTION
Designed a custom STM32 4-layer PCB with onboard high-precision IMU, barometer, flash logger, and dedicated 400kHz PWM motor output timers.
SYSTEM OVERVIEW & ARCHITECTURE
Features a custom 32-bit ARM Cortex processor running modular C++ attitude PID calculation loops at 1kHz update rates.
SYSTEM ARCHITECTURE BLOCK DIAGRAM FLOW:
SPI IMU Polling Interrupt (1kHz) → Quaternion Madgwick Filter → PID Controller → PWM Motor Timers → ESCs.
KEY TECHNICAL HIGHLIGHTS:
- ✓Custom 4-layer PCB impedance-controlled layout in KiCad.
- ✓1kHz deterministic PID attitude control loop in C++.
HARDWARE & ELECTRONICS
- Custom 4-Layer PCB
- STM32F4 Microcontroller
- BMI270 IMU Sensor
- SPI Flash Memory
- Low-Noise LDO Regulators
SOFTWARE & FIRMWARE
- Embedded C++
- KiCad PCB
- STM32CubeIDE
- OpenOCD
ALGORITHMS & CONTROL LOOPS
- Madgwick Orientation Quaternion Filter
- PID Control Loop with Anti-Windup
- PWM Duty Cycle Generator
COMMUNICATION PROTOCOLS
- SPI
- I2C
- UART DMA
- PWM
ENGINEERING CHALLENGES OVERCOME
- Routing high-density SMT microcontroller packages and keeping high-power switching noise away from sensitive analog sensor traces.
MY DIRECT CONTRIBUTIONS
- Designed full schematic and PCB layout, hand-soldered SMD components using stencil paste reflow, and wrote full bare-metal firmware stack.
VALIDATED SYSTEM RESULTS
- ▸Successfully validated 1kHz attitude stabilization on custom hardware test bench.
KEY ENGINEERING LESSONS LEARNED
- ▸Dedicated 4-layer PCBs with continuous ground planes drastically reduce IMU sensor noise floor compared to 2-layer boards.