Cm4 drone

BCFlight

BCFlight is an open-source Linux-based Raspberry Pi drone and ground controller system, offering a complete solution for flight control, stabilization, and telemetry.

Key Features

Performance

• Low resource usage : ~25% CPU and ~100MB RAM on Raspberry Pi 4
• High frequency : Sensors and stabilizer update rate up to 8kHz (on RPi4)
• Ultra-low latency : ~5ms controls latency, ~50ms video latency over composite
• Stabilization : Up to 8 motors with customizable configuration matrix

Motor Protocols

• DShot (150 & 300) - Recommended
• OneShot125 and OneShot42
• Standard PWM

Communication

• WiFi/Ethernet : Standard TCP/UDP/IP
• Raw WiFi : Based on wifibroadcast
• Radio : nRF24L01, SX1276/77/78/79 (FSK/LoRa)
• S-BUS : Limited functionality support

Video & Recording

• Composite output : Direct connection to 5GHz VTX modules, with SmartAudio support
• Multi-camera recording : MKV format, up to ~120 MPix/s total throughput
• Gyroflow output : Compatible with Gyroflow for video stabilization
• Live HUD : Real-time telemetry, battery status, speed, acceleration

Configuration

• LuaJIT : Flexible configuration and customizable event handling
• User code : Execution of custom Lua functions
• Full API : Access to all systems

Architecture

The project consists of three main components:

flight/ - Flight Controller

Core system managing:

• Main thread : Sensor data collection, attitude calculation, stabilization
• Controller thread : User input reception, telemetry transmission
• Power thread : Battery monitoring and current consumption

controller_pc/ - PC Interface

Configurable GUI client for:

• Remote control via PC
• Sensor and telemetry visualization
• Advanced configuration

controller_rc/ - Remote Control

Portable control interface with:

• Touchscreen support
• Adapted user interface
• Lua configuration

Supported Sensors

IMUs

• InvenSense ICM-42605, ICM-20608, MPU-9250, MPU-9150, MPU-6050
• STMicroelectronics L3GD20H, LSM303

Altimeters/Barometers

• Bosch BMP180, BMP280

Others

• HC-SR04 (distance sensors)
• ADS1015/ADS1115 (ADC)

Installation

Pre-built Images

Automatically generated images based on Raspbian:

• SSH : root:bcflight by default
• System : Read-only by default (security)
• Flight Service : Disabled by default for configuration

¹ DShot and composite output can be enabled via /boot/config.txt and /var/flight/config.lua

Building from Source

PC Controller (Ubuntu/Debian)

# Dependencies
sudo apt-get install nasm qtmultimedia5-dev qtbase5-dev qtchooser qt5-qmake qtbase5-dev-tools libnl-3-dev libnl-genl-3-dev libnl-route-3-dev libiw-dev libfftw3-dev libqscintilla2-qt5-dev

# Build
git clone https://github.com/dridri/bcflight.git
cd bcflight/controller_pc
cmake -DCMAKE_BUILD_TYPE=Release -S . -B build
cd build && make -j$(nproc)
./controller_pc

Flight Controller (Raspberry Pi)

# Dependencies
sudo apt update
sudo apt install git pkg-config cmake make g++ libc6-dev libraspberrypi-dev libiw-dev libdrm-dev libgbm-dev libcamera-dev libgles2-mesa-dev libgps-dev libasound2-dev libcrypt-dev zlib1g-dev libpng-dev libshine-dev libavformat-dev libavutil-dev libavcodec-dev libpigpio-dev lua5.3 libfftw3-dev

# Build
git clone https://github.com/dridri/bcflight
cd bcflight/flight
cmake -Dboard=rpi -Ddebug=1 -S . -B build
cd build && make -j$(nproc)

Configuration

Basic Configuration Example

-- Frame configuration (quadcopter)
frame = Multicopter {
    maxspeed = 1.0,
    air_mode = {
        trigger = 0.25,
        speed = 0.15
    },
    motors = {
        DShot( 4 ), DShot( 5 ), DShot( 6 ), DShot( 7 )
    },
    matrix = {
        Vector( -1.0,  1.0, -1.0, 1.0 ),
        Vector(  1.0,  1.0,  1.0, 1.0 ),
        Vector( -1.0, -1.0,  1.0, 1.0 ),
        Vector(  1.0, -1.0, -1.0, 1.0 )
    }
}

-- IMU configuration
imu = IMU {
    gyroscopes = { imu_sensor.gyroscope },
    accelerometers = { imu_sensor.accelerometer },
    filters = {
        rates = { input = Vector( 80, 80, 80 ), output = Vector( 0.25, 0.25, 0.25 ) },

Demo

More videos on YouTube @drichfpv

User Interface

PC Controller

Sensors and Telemetry

Hardware

Custom CM4 Carrier Board

Features:

• 5V 3A LM22676 regulator (max 42V input)
• ADS1115 ADC for battery voltage measurement
• Dual RFM95W radio sockets with external antennas
• High-precision ICM-42605 IMU
• BMP581 barometer
• Dual CSI camera connectors
• Direct composite video output to VTX

Hardware Photos

Documentation

• Configuration
• Sensors
• Motors
• Radio

Contributing

Contributions are welcome! The project is licensed under GPL v3.

License

This project is distributed under the GNU General Public License v3.0. See the LICENSE file for more details.

Useful Links

• CI/CD : ci.drich.fr
• Images : bcflight.drich.fr
• CAD : View on CADLAB.io

⚠️ Warning : This software is provided for educational and research purposes. Drone usage can be dangerous. Please respect local regulations and use at your own risk.