Talon is a modern, privacy-focused Android application for tracking body composition and fitness progress. Designed to work with Bluetooth smart scales, it provides detailed insights into your health metrics without relying on cloud services.

✨ Features

• 🧬 Scientifically Calibrated: Body Fat algorithm derived from 59,430 clinical profiles (CDC NHANES dataset).
• 📐 DEXA-Grade Accuracy: Our formula correlates raw Bio-electrical Impedance (BIA) with medical Dual-Energy X-ray Absorptiometry (DEXA) scans, replacing generic commercial approximations.
• ⚡ Direct BLE Connection: Reverse-engineered support for "OKOK" protocol scales (and compatible generic chipsets).
• 🚫 Ad-Free & Account-Free: No cloud servers, no sign-ups, no ads. Your biometric data stays on your device.
• 🔗 Google Fit Integration: Seamless sync using the modern Android Health Connect API.

📊 Comprehensive Metrics

Track more than just weight. Talon captures and analyzes:

• Weight & BMI (with color-coded categories)
• Body Fat %
• Muscle Mass
• Water %
• Bone Mass
• Metabolic Age
• BMR (Basal Metabolic Rate)
• Impedance

🔬 Scientific Basis

Most generic smart scales use obscure, proprietary formulas to estimate Body Fat %. Talon takes a transparent, data-driven approach.

We trained a Linear Regression Machine Learning model on the NHANES 1999-2004 dataset (National Health and Nutrition Examination Survey) provided by the US CDC. This specific period is considered the "Golden Age" of body composition data, as it contains both:

1. Input: Raw BIA Resistance (Ohms) - what your scale measures.
2. Ground Truth: Whole-body DEXA Scans - the medical gold standard for body fat.

The Result: A custom formula optimized on 59,430 real human profiles to translate your scale's electrical resistance into meaningful health metrics with minimized error.

Formula logic: BodyFat% = f(Height²/Impedance, Weight, Age, Gender)

📈 Visualization & Trends

• Interactive Charts for all metrics (powered by Vico)
• Filter data by Week, Month, 3 Months, Year, or All Time
• View key statistics: Average, Minimum, Maximum, and Change over time

🎯 Goal Tracking

• Set personalized goals for Weight, Body Fat, or Muscle Mass
• Track progress with visual indicators
• Set deadlines and receive achievement alerts

💾 Data Management

• Offline First: All data is stored locally on your device using Room Database.
• Export: Export your data to CSV for analysis in spreadsheets.
• Backup: Create full JSON backups of your history and settings.
• Edit/Delete: Full control to modify or remove incorrect measurements.

⚙️ Customization

• Dark/Light Theme support
• Reminders: Schedule daily weigh-in notifications
• Onboarding: Guided setup for new users

📸 Screenshots

Measure Tab	Scanning UI
Empty State	Navigation
Settings	Help

🛠️ Tech Stack

• Android: Kotlin, Jetpack Compose (Material 3), MVVM, Room Database.
• Bluetooth: Android BLE Scanner & GATT.
• Data Science: Python (pandas, scikit-learn) for algorithm calibration

• Language: Kotlin
• UI: Jetpack Compose (Material 3)
• Architecture: MVVM (Model-View-ViewModel)
• Local Storage: Room Database (SQLite)
• Asynchronous: Coroutines & Flow
• Charts: Vico
• Background Tasks: WorkManager
• Navigation: Compose Navigation Suite

📂 Project Structure

The project follows a layered architecture based on Android best practices, separating concerns into UI, Data, and Domain layers:

com.aquilesorei.talon
├── ui/              # Presentation Layer
│   ├── screens/     # Composable screens (Home, History, etc.)
│   ├── components/  # Reusable UI components
│   └── theme/       # Theme definitions
├── domain/          # Domain Layer
│   ├── models/      # Business objects (Measurement, UserProfile)
│   └── usecases/    # Business logic
├── data/            # Data Layer
│   ├── local/       # Local storage (Room DB, DAOs, Entities)
│   └── repository/  # Single source of truth for data
├── viewmodels/      # State holders
├── workers/         # Background tasks (WorkManager)
└── utils/           # Utility classes

🚀 Getting Started

Prerequisites

• Android Studio Ladybug or newer
• JDK 17+
• Android Device with Bluetooth LE support (min SDK 31 recommended)

Installation

1. Clone the repository:

   git clone https://github.com/Aquilesorei/talon.git

2. Open the project in Android Studio.
3. Sync Gradle files.
4. Build and run on your device or emulator.

Note: Bluetooth scanning requires a physical device. Emulators cannot scan for Bluetooth Low Energy devices.

📱 Usage

1. Connect Scale: Go to the Measure tab and tap the Bluetooth icon to scan for your supported smart scale.
2. Weigh In: Stand on the scale. The app will automatically capture your metrics.
3. Track: Switch to the Charts tab to see your trends.
4. Set Goals: Use the Goals tab to define your targets.
5. Settings: Customize your theme and notification preferences in Settings.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.