SmartConnect — Bluetooth Scanner & NFC Tap-to-Share

A modern Android app built with Kotlin, Jetpack Compose, MVVM + Clean Architecture, and Firebase for Bluetooth device discovery and NFC-based data sharing.

Features

• Bluetooth Scanner — Discover nearby BT devices with real-time signal strength, device type icons, and one-tap pairing
• Paired Devices — View all paired devices, send test data via BT socket
• NFC Tap & Share — Read NFC tags, write payloads (text, URL, contact, WiFi creds, custom data) to tags
• Transfer History — All BT/NFC transfers logged in Room DB with Firebase Firestore sync
• Runtime Permissions — Accompanist permissions for BT/NFC on Android 12+

Architecture

app/                          ← UI layer (Compose, ViewModels, Navigation, Hilt DI)
core/
  ├── common/                 ← Shared utilities (Resource, Constants)
  ├── domain/                 ← Models, Repository interfaces, Use Cases
  └── data/                   ← Bluetooth controller, NFC controller, Room, Firebase, Mappers

Tech Stack

Layer	Technology
UI	Jetpack Compose, Material 3, Accompanist Permissions
State	StateFlow, collectAsStateWithLifecycle
Async	Kotlin Coroutines + Flow
DI	Dagger Hilt
Bluetooth	Android BluetoothAdapter, BroadcastReceiver, RFCOMM Socket
NFC	NfcAdapter, NDEF read/write, Foreground Dispatch
Database	Room
Cloud	Firebase Firestore (transfer history sync)
Build	Gradle Kotlin DSL, Version Catalog

Setup

1. Clone and open in Android Studio
2. Add google-services.json from Firebase Console to app/ folder
3. Run on a physical device (Bluetooth/NFC don't work on emulators)

Screens

1. Scanner — Tap FAB to scan, see devices with signal bars, tap to connect
2. Paired — List of bonded devices with send button
3. NFC — Status card, payload type selector, read/write buttons
4. History — Transfer log with direction arrows, cloud sync button