ZenTuner

A minimalist chromatic tuner for Android with a retro-inspired UI featuring an arc gauge and segmented note display.

Features

• Real-time pitch detection using autocorrelation algorithm
• Arc gauge indicator with spring animation
• Seven-segment style note display
• Adjustable microphone gain threshold via rotary knob
• Supports full chromatic range (C0 - B8)
• Standard guitar tuning detection (E2, A2, D3, G3, B3, E4)

Architecture

The project follows a Feature Slice Architecture with clean separation of concerns:

core/
  BaseSharedViewModel.kt        # Base ViewModel with State/Action/Event pattern
  UseCase.kt                    # UseCase interface

feature/tuner/
  presentation/
    screen/TunerScreen.kt       # Thin adapter (ViewModel -> View)
    view/                       # Pure UI composables
    viewmodel/                  # ViewModel, ViewState, ViewEvent, ViewAction
  domain/
    model/                      # Note, PitchResult, SymbolSegment
    repository/                 # ITunerRepository interface
    usecase/                    # ObservePitch, StartTuner, StopTuner
  data/
    datasource/                 # AudioRecorder, PitchDetector
    repository/                 # TunerRepository implementation
  di/                           # Koin DI module

Key patterns

• BaseSharedViewModel<State, Action, Event> with obtainEvent() for unidirectional data flow
• UseCase interface with suspend fun execute(params): Result<T>
• Koin for dependency injection
• Jetpack Compose for UI with @Preview support

Tech stack

• Kotlin
• Jetpack Compose (Material 3)
• Koin (DI)
• Kotlin Coroutines & Flow
• JUnit 4 + MockK (testing)

Requirements

• Android SDK 24+ (Android 7.0)
• Microphone permission (requested at runtime)

Build & Run

./gradlew assembleDebug
./gradlew installDebug

Tests

./gradlew test

License

All rights reserved.