DexcomCatcher

An Android application that captures and displays real-time glucose data from Dexcom Continuous Glucose Monitoring (CGM) devices.

Overview

DexcomCatcher is a lightweight Android app that listens for Dexcom CGM broadcasts and displays glucose readings in a simple, easy-to-read interface. The app runs as a foreground service to continuously monitor glucose data in the background.

Features

• Real-time Glucose Monitoring: Captures live glucose readings from Dexcom CGM devices
• Trend Indicators: Displays glucose trend arrows (rising, falling, stable)
• Background Service: Continues monitoring even when the app is not in the foreground
• Notification Support: Runs as a foreground service with persistent notification
• Simple UI: Clean, minimal interface showing current glucose value, trend, and timestamps

Requirements

• Android 11 (API level 30) or higher
• Dexcom CGM app installed and configured
• Permission to access Dexcom CGM data

Permissions

The app requires the following permissions:

• com.dexcom.cgm.EXTERNAL_PERMISSION - Access to Dexcom CGM data
• android.permission.FOREGROUND_SERVICE - Run background service
• android.permission.POST_NOTIFICATIONS - Show notifications

Installation

1. Clone the repository:

   git clone <repository-url>
   cd DexcomCatcher

2. Open the project in Android Studio

3. Build and install the APK:

   ./gradlew assembleDebug

4. Install on your Android device and grant the required permissions

Usage

1. Launch the app
2. Grant the Dexcom external permission when prompted
3. The app will start monitoring glucose data automatically
4. View real-time glucose readings on the main screen
5. The service will continue running in the background

Technical Details

Architecture

• MainActivity: Main UI activity that displays glucose data
• DexcomService: Foreground service that manages the broadcast receiver
• DexcomReceiver: Broadcast receiver that listens for Dexcom CGM data

Data Structure

The app processes glucose data from Dexcom broadcasts containing:

• Glucose value (mg/dL)
• Trend arrow direction
• Timestamp information
• Historical readings (up to 288 data points)

Key Components

• Service: DexcomService - Manages background operation
• Receiver: DexcomReceiver - Handles Dexcom broadcasts
• Activity: MainActivity - Main user interface

Configuration

Build Configuration

• Minimum SDK: 30 (Android 11)
• Target SDK: 33 (Android 13)
• Compile SDK: 33

Dependencies

implementation 'androidx.appcompat:appcompat:1.6.1'
implementation 'com.google.android.material:material:1.9.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'

Development

Building from Source

1. Ensure you have Android Studio and Java 17+ installed
2. Clone the repository
3. Open in Android Studio
4. Sync Gradle files
5. Build and run on your device

Testing

Run unit tests:

./gradlew test

Run instrumented tests:

./gradlew connectedAndroidTest

Troubleshooting

Common Issues

1. Permission Denied: Ensure Dexcom app is installed and the external permission is granted
2. No Data Received: Verify Dexcom CGM is paired and transmitting data
3. Service Stops: Check battery optimization settings for the app

Logs

Monitor app logs using:

adb logcat | grep DexcomCatcher

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

Disclaimer

This application is for educational and personal use only. It is not intended for medical diagnosis or treatment. Always consult with healthcare professionals for medical decisions.

Support

For issues and questions, please open an issue on the GitHub repository.