Released September 2025
Chromatic Tuner
A modern Android chromatic tuner with real-time FFT analysis, parabolic-interpolation pitch detection, and a Material 3 cents-offset meter — always listening, no start button.
kotlinandroidaudiofftjetpack-compose
About
A chromatic tuner app for Android that does one thing well: hold your phone near an instrument and it tells you what note you’re playing and how far off you are, in cents. There’s no start/stop button — it’s always listening, with a volume threshold filtering out background noise.
Audio Pipeline
- Microphone capture at 44.1 kHz with a 4096-sample buffer
- RMS volume gate to ignore ambient noise
- Real-time FFT with a custom implementation
- Peak detection with parabolic interpolation for sub-bin frequency precision
- Frequency → note mapping via equal temperament, with a ±50-cent visual meter
Technical Details
- Language: Kotlin
- UI: Jetpack Compose with Material 3, dark/light themes, portrait and landscape
- Architecture: MVVM with reactive state
- Compatibility: Android 8.0+ (min SDK 26)