A personal learning project — building a differential-drive robot from scratch using ROS2 on a Raspberry Pi 4, an ESP32 for real-time motor/sensor control, and a fully 3D-printed chassis.
Full documentation → dagebg.github.io/ros2-self-balancing-robot
The target end state is a two-wheeled self-balancing robot that:
- Balances itself using IMU sensor fusion feedback and a PID controller running on the ESP32
- The ESP32 runs a fast real-time balance loop (2xIMU → PID → motor commands)
- ROS2 on the Pi acts as the high-level layer, sending velocity targets without caring about the internal balance loop
- The chassis is being designed from scratch in Autodesk Fusion and Siemens NX and 3D-printed on a BambuLab P1S
- Controlling the controller over network with webapp
| Component | Role |
|---|---|
| Raspberry Pi 4B 4GB | Main computer running ROS2 |
| ESP32 DevKit C V4 | Real-time motor control + IMU bridge |
| 2× N20 100 RPM + Hall encoders | Drive wheels + wheel odometry |
| TB6612FNG dual motor driver | Motor direction + PWM speed control |
| MPU-9250 9-DOF IMU | Accelerometer, gyroscope, magnetometer |
| MPU-6050 6-DOF IMU | Accelerometer, gyroscope |
| 2x 7.4V 2000mAh Li-Ion 2S | Main power source |
| 3x HW-140 DC-DC Buck Boost Converter | Power converter |
| 3D-printed chassis + wheels | Custom mechanical platform |
The robot uses a multi-rail power architecture with dedicated buck converters for compute and embedded subsystems.
This robot uses two physically mounted IMUs at different locations and orientations for sensor fusion experimentation.
| IMU | Location | Orientation | Function |
|---|---|---|---|
| MPU-9250 | Lower deck | Facing forward | Primary IMU, 9-DOF orientation sensing |
| MPU-6050 | Second deck | Facing backward | Secondary IMU, comparison/reference sensing |
The robot electronics are documented in KiCad with a complete schematic of the main system.
Files:
ros2-diffdrive-robot/
├── ros2_ws/ ROS2 workspace (packages: diff drive, navigation, etc.)
├── firmware/ ESP32 firmware (motor controller, IMU bridge)
├── mechanical_hardware CAD design & wiring schematics
└── docs/ Architecture notes + Sphinx documentation
Early WIP — ROS2 workspace and firmware development in progress.