Drone Flight Controller

ESP32-Quadcopter-FlightController

Open-source ESP32-based flight controller for quadcopters, featuring sensor fusion, nested PID control, motor mixing, real-time Wi-Fi PID tuning, and a custom KiCad PCB with support for GPS and FPV modules.

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📘 Introduction

This project is a fully custom ESP32-based quadcopter flight controller, built from scratch to provide complete hardware and firmware flexibility.
Unlike commercial closed-source flight controllers, this system allows direct modification of IMU handling, PID algorithms, motor mixing, and communication layers—making it ideal for learning, research, and UAV experimentation.

The controller runs an 83 Hz control loop, uses a complementary filter for real-time roll/pitch estimation, and stabilizes the quadcopter using nested PID loops (Angle + Rate).
A built-in Wi-Fi interface enables on-the-fly PID tuning and telemetry, eliminating the need to reflash firmware between adjustments.

This repository includes the complete firmware, custom KiCad PCB design, calibration and testing utilities, project media, and a comprehensive technical report documenting the system design and implementation.

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⭐ Highlights

• Custom ESP32-based flight controller firmware
• Complementary filter for attitude estimation
• Dual-loop PID control for roll, pitch, and yaw
• Motor mixing for X-configuration quadcopters
• Real-time Wi-Fi tuning dashboard
• Custom two-layer PCB with expansion support
• Stable and tested flight performance (90–95%)
• Open-source and fully modifiable

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🖼 Drone Image

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🔧 Features

• Real-time IMU data acquisition using MPU6050
• Complementary filter–based angle estimation
• Nested PID loops for angle and rate stabilization
• PWM signal generation for ESCs
• i-BUS / PWM receiver input handling
• Wi-Fi HTTP server for dashboard + tuning
• Support for barometer (alt-hold), GPS, and FPV modules
• Modular code structure for easy experimentation

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🛠 Hardware Used

• ESP32 DevKit V1
• MPU6050 IMU
• RS-2212 920KV motors + 30A ESCs
• FlySky FS-i4X receiver
• 3S Li-Po battery
• F450 frame
• Custom-designed flight controller PCB

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📂 Repository Contents

• Firmware/

  • Main_Firmware/ – Main ESP32-based quadcopter flight controller firmware
  • Testing_Calibration/ – Calibration, testing, and Wi-Fi PID tuning utilities

• Hardware/

  • Drone Flight Controller/ – Complete KiCad project (schematic, PCB layout, and project files)
  • FC Gerber.zip – PCB manufacturing (Gerber) files
  • PCB View.pdf – PCB layout overview
  • Schematic.pdf – Flight controller circuit schematic

• Media/

  • Drone/ – Drone assembly, flight controller, and hardware images
  • Test Flight and Calibration/ – Flight test videos, calibration recordings, and PID response graph

• Technical Report.pdf – Comprehensive technical documentation covering hardware design, firmware architecture, implementation, and testing

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💻 Software Requirements

• Arduino IDE 2.x
• ESP32 Arduino Core
• KiCad 9.x (for PCB design)

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📚 Libraries Used

• Wire – I²C communication
• ESP32Servo – ESC PWM control
• WiFi – Wireless communication
• AsyncTCP – Asynchronous TCP networking
• ESPAsyncWebServer – Web-based PID tuning dashboard
• SPIFFS – Web dashboard file storage

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🚀 Getting Started

Follow the steps below to configure and fly the quadcopter for the first time.

1. Hardware Setup

• Assemble the quadcopter and connect all hardware components.
• Wire the ESP32, MPU6050, ESCs, receiver, and motors according to the provided schematic.

2. Verify Receiver and ESCs

• Upload the firmware from Firmware/Testing_Calibration/Receiver_PWM_Testing/ to verify proper receiver operation.
• Upload the firmware from Firmware/Testing_Calibration/ESC_Calibration/ and calibrate all ESCs.

3. Calibrate the IMU

• Upload the firmware from Firmware/Testing_Calibration/IMU_Calibration/.
• Place the quadcopter on a level surface and perform the IMU calibration.
• Copy the generated accelerometer and gyroscope offset values into both the main flight controller firmware and the PID tuning firmware.

4. Tune the PID Controller

• Upload the firmware from Firmware/Testing_Calibration/PID_Tuning_Webserver/.
• Connect to the ESP32 Wi-Fi access point and open the PID tuning dashboard.
• Tune the roll, pitch, and yaw PID gains until stable flight performance is achieved.
• Copy the optimized PID values into the main flight controller firmware.

5. Upload the Main Flight Controller Firmware

• Open Firmware/Main_Firmware/Flight_Controller_v2/Flight_Controller_v2.ino.
• Update the firmware with the calibrated IMU offsets and tuned PID gains.
• Upload the firmware to the ESP32.

6. Perform Flight Testing

• Verify the motor rotation direction and propeller orientation.
• Perform an initial low-throttle hover test in a safe, open area.
• Fine-tune the PID gains as required to achieve stable and responsive flight.