bscm-dbus-cpp

C++ application to use BlueZ over D-Bus to scan for Bluetooth devices, connect to them, and manage GATT characteristics with notifications.

Features

• Scan for Bluetooth devices using BlueZ over D-Bus
• Filter devices by desired service UUIDs
• Connect/disconnect to/from Bluetooth devices
• Discover GATT characteristics
• Enable/disable notifications on characteristics
• Read from and write to characteristics
• Real-time notification processing with terminal output

Requirements

• Linux system with BlueZ installed
• D-Bus development libraries (libdbus-1-dev)
• CMake (3.10 or higher)
• C++17 compatible compiler

Building

# Install dependencies (Ubuntu/Debian)
sudo apt install libdbus-1-dev build-essential cmake

# Build the application
mkdir build
cd build
cmake ..
make

Usage

Run the application as root or with appropriate D-Bus permissions for BlueZ:

sudo ./bscm-bluetooth-manager

Main Menu Options

1. Scan for devices - Discover nearby Bluetooth devices
2. Set service filter - Filter devices by service UUIDs (optional)
3. List devices with desired services - Show filtered devices
4. Connect to device - Establish connection to a selected device
5. Disconnect from device - Disconnect from a connected device
6. Manage characteristics - Work with GATT characteristics
7. Process notifications - Listen for notifications for 10 seconds

Service Filtering

You can filter devices by service UUIDs. Enter UUIDs comma-separated:

• Example: 0000180f-0000-1000-8000-00805f9b34fb, 0000180a-0000-1000-8000-00805f9b34fb
• Enter none to clear the filter and show all devices

Characteristic Management

Once connected to a device, you can:

• Enable/disable notifications on characteristics
• Read characteristic values
• Write data to characteristics (in hex format)
• View characteristic UUIDs and properties

Notification Output

When notifications are enabled and received, they are displayed in the terminal with:

• The characteristic path that sent the notification
• Raw data in hexadecimal format
• ASCII representation (printable characters only)

Example Session

1. Start the application and scan for devices
2. Set a service filter (e.g., Battery Service: 0000180f-0000-1000-8000-00805f9b34fb)
3. List filtered devices and select one to connect
4. Explore characteristics and enable notifications on desired ones
5. Write commands to control characteristics
6. Monitor notifications in real-time

Architecture

• dbus_helper.cpp/h - Low-level D-Bus communication wrapper
• bluetooth_manager.cpp/h - High-level BlueZ interface and device management
• main.cpp - CLI interface and main application logic

Troubleshooting

• Ensure BlueZ is running: sudo systemctl status bluetooth
• Check D-Bus permissions for BlueZ access
• Run as root if experiencing permission issues
• Verify Bluetooth adapter is available: hciconfig