Bluetooth Distance Measurement App

A Flutter application that measures distance between devices using Bluetooth Low Energy (BLE) technology. The app provides comprehensive device discovery with detailed information extraction and real-time distance tracking.

Features

🔍 Enhanced Device Discovery

The app provides detailed information about discovered BLE devices:

Device Identification

• Device ID: MAC address (Bluetooth address) - unique 48-bit identifier (e.g., 6A:2F:01:17:2E:AE)
• Device Names: Extracted from advertising packets when available
• RSSI: Received Signal Strength Indicator in dBm for signal strength analysis

Smart Device Classification

The app automatically categorizes devices based on service UUIDs and manufacturer data:

• Apple Device - Recognized by manufacturer codes
• Samsung Device - Samsung Electronics devices
• Smartphone - Phone-related service UUIDs
• Audio Device - Headphones, speakers, audio peripherals
• Fitness Tracker - Health and fitness monitoring devices
• Smart Watch - Wearable devices
• Heart Rate Monitor - Medical monitoring devices
• Medical Device - Healthcare equipment
• IoT Device - Internet of Things devices
• Unknown Device - Fallback for unrecognized devices

Manufacturer Detection

Extracts manufacturer information using Company Identifier Codes (CIC):

• Apple (0x004C, 0x0013, and extensive range)
• Samsung Electronics (0x0009, 0x0012, 0x0015)
• Microsoft (0x0006)
• Qualcomm (0x000A and extensive range)
• Broadcom, Texas Instruments, Nordic Semiconductor, and many more

📊 Real-Time Distance Tracking

• Live RSSI Monitoring: Continuous signal strength measurement
• Distance Calculation: Uses RSSI-based distance estimation with configurable parameters
• Signal Smoothing: Moving average window for stable readings
• Real-time Updates: Live distance and signal strength display

🎨 User Interface Features

• Color-coded Device Types: Visual identification with distinct colors
• Comprehensive Device Cards: Detailed information display
• Status Indicators: Bluetooth state, scanning status, tracking status
• Error Handling: Clear error messages and diagnostic tools
• Responsive Design: Optimized for mobile devices

Technical Implementation

Architecture

• Provider Pattern: State management using Provider package
• Stream-based Scanning: Real-time BLE device discovery
• Modular Design: Separated concerns with dedicated managers and providers

Core Components

BleManager

• BleDeviceInfo class with comprehensive device information
• _extractManufacturerName() - Decodes manufacturer codes
• _determineDeviceType() - Identifies device types from service UUIDs
• _extractAdditionalData() - Extracts advertising packet data
• scanDevicesComprehensive() - Enhanced scanning with deduplication
• testBleScanning() - Diagnostic capabilities

DistanceProvider

• Real-time RSSI tracking with moving average smoothing
• Automatic scan restart on interruption
• Error handling and state management
• Stream-based architecture for live updates

DistanceCalculator

• RSSI-to-distance conversion using path loss model
• Configurable transmission power and path loss exponent
• Accurate distance estimation with environmental considerations

Service UUID Detection

The app identifies device types by analyzing service UUIDs:

• Heart Rate: 0x180D, 0x2A37
• Fitness/Health: 0x1812, 0x1816, 0x1818, 0x1819
• Phone: 0x1800, 0x1801, 0x110E, 0x110F
• Audio: 0x110A, 0x110B, 0x110C, 0x110D
• Medical: 0x1808, 0x1809, 0x180A, 0x180B
• IoT: 0x1815, 0x181A

Usage

Getting Started

1. Grant Permissions: Allow location and Bluetooth permissions when prompted
2. Enable Bluetooth: Ensure Bluetooth is turned on
3. Start Scanning: Tap the play button to begin device discovery
4. Select Device: Tap on a discovered device to start distance tracking
5. Monitor Distance: View real-time distance and signal strength readings

Features

• Device Discovery: Comprehensive scanning with detailed device information
• Distance Tracking: Real-time distance measurement with signal smoothing
• Diagnostic Tools: Built-in BLE diagnostics for troubleshooting
• Error Handling: Clear error messages and status indicators

Requirements

• Flutter: 3.0+ (SDK 3.5.4+)
• Android: 6.0+ (API level 23+)
• iOS: 11.0+
• Hardware: Physical device (BLE scanning has limited support on emulators)
• Permissions: Location and Bluetooth permissions required

Dependencies

• flutter_blue_plus: ^1.35.5 - BLE functionality and device management
• provider: ^6.1.5 - State management and reactive programming
• permission_handler: ^12.0.1 - Permission management
• cupertino_icons: ^1.0.8 - iOS-style icons

Important Notes

Platform Considerations

• Android Emulators: Limited BLE support - test on physical devices for best results
• iOS Simulators: BLE functionality may be restricted - use physical devices
• Location Services: Required for BLE scanning on Android devices

Accuracy Considerations

• Environmental Factors: Distance accuracy depends on environment (walls, interference)
• Device Variations: Different devices may have varying transmission power
• Signal Fluctuations: RSSI values can vary due to multipath propagation
• Calibration: Distance calculation uses standard path loss model (may need device-specific calibration)

Troubleshooting

• Use the built-in diagnostic tool (bug icon) to check BLE status
• Ensure target devices are in discoverable/advertising mode
• Check that location services are enabled
• Verify Bluetooth permissions are granted
• Test on physical devices rather than emulators

Project Structure

lib/
├── ble/
│   ├── ble_manager.dart          # BLE device management and scanning
│   └── distance_calculator.dart  # RSSI to distance conversion
├── providers/
│   └── distance_provider.dart    # State management for distance tracking
├── screens/
│   ├── device_list_screen.dart   # Device discovery and selection
│   └── home_screen.dart         # Distance tracking interface
└── main.dart                    # App entry point