Mini Drone — Drone Flight

 

Overview

This branch contains the onboard firmware responsible for reading the IMU, estimating the drone attitude, receiving remote-control commands, running the stabilization controllers, and driving four motors.

The project is built with PlatformIO for the ESP32-C3 using the Arduino framework.

Main Features

• MPU6500 IMU interface over SPI
• Madgwick attitude estimation
• Cascaded angle and angular-rate PID control
• Four-motor mixing for roll, pitch, and yaw correction
• ESP-NOW command and heartbeat communication
• Arm/disarm handling
• Communication-loss failsafe with gradual throttle reduction
• Modular source layout for communication, control, drivers, estimation, and hardware abstraction

Hardware

Component	Description
Flight controller	ESP32-C3 development board
IMU	MPU6500 accelerometer and gyroscope
Motors	Four brushed DC motors
Propellers	Four two-blade propellers
Frame	Custom mini-drone PCB frame
Power	External battery through the onboard power connector

Software Architecture

Remote Controller
       |
       | ESP-NOW commands and heartbeat
       v
Communication
       |
       v
Flight-Control Loop
       |
       +--> MPU6500 Driver
       |
       +--> Madgwick Estimator
       |
       +--> Angle PID
       |
       +--> Rate PID
       |
       +--> Motor Mixer
       |
       v
Motor HAL
       |
       v
Four Motors

Project Structure

.
├── docs/                   Documentation and reference material
├── include/                Shared public headers
├── lib/                    Project libraries
├── src/
│   ├── communication/      ESP-NOW communication and protocol
│   ├── control/            PID controller
│   ├── drivers/            MPU6500 driver
│   ├── estimator/          Madgwick attitude estimator
│   ├── hal/                SPI bus and motor abstraction
│   └── main.cpp            Initialization and main flight loop
└── platformio.ini          PlatformIO configuration

Requirements

• Visual Studio Code
• PlatformIO extension or PlatformIO Core
• ESP32-C3 development board
• USB data cable

Build

Clone the drone-flight branch:

git clone --branch drone-flight --single-branch \
    https://github.com/haikevins/mini-drone.git

cd mini-drone

Build the firmware:

pio run

Upload

Connect the ESP32-C3 and run:

pio run --target upload

The default upload port is configured as:

/dev/ttyACM0

Change upload_port in platformio.ini when the board appears on another port.

Serial Monitor

pio device monitor

Default monitor speed:

115200 baud

Basic Runtime Flow

setup()
  ├── Initialize MPU6500
  ├── Initialize PID controllers
  ├── Initialize ESP-NOW
  └── Initialize motors

loop()
  ├── Read and filter IMU data
  ├── Update Madgwick attitude estimate
  ├── Check command heartbeat and failsafe state
  ├── Update roll and pitch targets
  ├── Run angle PID controllers
  ├── Run angular-rate PID controllers
  ├── Mix corrections into four motor outputs
  └── Write motor commands

Status

This project is under active development and should be treated as experimental flight-control firmware.