Auspex

A modern, open-source USB OTG camera app for Android. No ads, no tracking, no sketchy permissions.

Why

Every OTG camera app on the Play Store is either:

• Built on ancient APIs (Android 6-era)
• From unknown developers with questionable privacy practices
• Choked with interstitial and rewarded ads
• Missing basic manual controls
• Prone to crashing on modern Android versions (14+)

This project replaces that mess with a clean Kotlin + Compose app using modern Android APIs and build standards.

Architecture

Hybrid backend approach:

1. Camera2 API (primary) — Used when the OEM has enabled external camera support (LENS_FACING_EXTERNAL). Clean, official, no native code needed.
2. UVCCamera (fallback) — Direct USB access via alexey-pelykh/UVCCamera. Works on any USB OTG-capable device regardless of OEM camera support.

The UI layer is completely unaware of which backend is active — both implement the same CameraInterface.

┌─────────────────────────────┐
│       Compose UI Layer      │
└──────────┬──────────────────┘
           │ CameraInterface
     ┌─────┴─────┐
     ▼           ▼
┌─────────┐ ┌────────────┐
│Camera2  │ │UVCCamera   │
│Backend  │ │(JNI/V4L2)  │
└─────────┘ └────────────┘

Tech Stack (2026 Standards)

• Language: Kotlin 2.3.10
• Build System: Gradle 9.6.1 + AGP 9.3.0 (Built-in Kotlin)
• UI: Jetpack Compose (2026.06.01 BOM) + Material 3 (Edge-to-Edge)
• DI: Hilt 2.60.1
• Camera: Camera2 API (primary), UVCCamera library (fallback)
• Video: MediaCodec (H.264) + MediaMuxer
• Target SDK: 37 (Android 17)
• Min SDK: 24 (Android 7.0)

Key Features

• Live Camera Preview
• Feed Capture : Photo capture (JPEG), Video recording (H.264 MP4)
• Manual Controls: Fine-grained control over exposure, gain, white balance, focus, and image processing (brightness/contrast/etc).
• Robust Hot-Plugging: Real-time USB device detection
• Diagnostics: Built-in runtime event logger for troubleshooting hardware communication issues.
• Modern Permissions: Compliant with Android 13+ Notification permissions and Android 14+ Foreground Service types.

Project Structure

app/src/main/kotlin/com/toyrobotworkshop/auspex/
├── AuspexApp.kt              # Application + Hilt
├── di/                       # Dependency injection modules
├── camera/                   # Camera abstraction layer
│   ├── CameraInterface.kt    # Unified interface
│   ├── CameraManager.kt      # Backend detection/factory
│   ├── camera2/              # Camera2 API backend
│   └── uvc/                  # UVCCamera JNI backend
├── ui/                       # Compose UI
│   ├── theme/                # Material 3 theme (dark/light/dynamic)
│   ├── main/                 # Screens (Camera, NoDevice, PreviewView)
│   ├── settings/             # Settings + diagnostics screen
│   └── navigation/           # Nav graph with auto-recovery logic
└── util/                     # Utilities
    ├── FileSaver.kt          # Cache-dir file output
    ├── UsbReceiver.kt        # USB plug/unplug detection
    ├── DiagnosticLogger.kt   # Runtime event logging
    └── RecordingService.kt   # Background recording service (Android 14+ compliant)

License

Apache 2.0