Reaction Wheel Balancing System
stm32 esp32 c++ pid bldc kicad pcb-design fusion360
Overview
A personal project: an inverted triangle that balances itself using a reaction wheel — no legs, no wheels on the ground. The angular momentum of the spinning reaction wheel corrects the tilt in real time.
Hardware
- Balance controller: STM32 running a fast PID loop reading an IMU
- Telemetry: ESP32 streaming state data over BLE to a phone/PC
- Actuator: BLDC motor with an inner current control loop for smooth torque output
- PCB: Custom board designed in KiCad integrating power, drivers, and MCU
- Chassis: Designed in Fusion 360, FDM printed
Control Architecture
The outer loop is a PID angle controller. The inner loop is a current (torque) controller on the BLDC, ensuring the reaction wheel responds quickly without mechanical resonance.
Status
Active — ongoing personal development (2026).