Interval Bell Android App

An Android application that allows users to set a time interval and receive bell notifications at regular intervals. Perfect for meditation, workouts, study sessions, or any activity that requires periodic reminders.

Features

• Google Timer-Style Time Input: Enter time intervals using an intuitive numeric keypad
  • Digits shift from right to left as you type (just like Google Timer)
  • Display shows hours, minutes, and seconds (HH:MM:SS format)
  • "00" button for quick double-zero entry
  • Backspace button to delete last digit (long press to clear all)
• Customizable Interval: Set any time interval up to 99h 59m 59s
• 26 Bell Sounds: Choose from a wide variety of bell tones with preview functionality:
  • Classic/Traditional: Classic Bell, Church Bell, Temple Bell, Chime, Grandfather Clock
  • Digital/Modern: Digital Beep, Notification, Alarm, Sci-Fi Alert, Radar Ping
  • Musical: Piano Chord, Xylophone, Harp, Music Box
  • Nature: Bird Chirp, Water Drop
  • Fun/Funny: Duck Quack, Robot Beep, Doorbell, Game Over, Celebration, Spaceship, Submarine, Magic Wand, Cow Bell, Boxing Bell
• Visual Countdown: See the time remaining until the next bell (in HH:MM:SS format)
• Vibration Feedback: Haptic feedback when the bell rings
• Background Operation: Timer continues running even when the app is in the background

Requirements

• Android 7.0 (API level 24) or higher
• Android Studio or compatible IDE
• Gradle 8.2.0 or higher

Building the App

1. Open the project in Android Studio
2. Sync Gradle files
3. Build the project (Build > Make Project)
4. Run on an emulator or physical device

Usage

1. Use the numeric keypad to enter your desired time interval:
   • Tap digits 0-9 to enter time (digits shift left like a calculator)
   • Use "00" for quick double-zero entry
   • Use "⌫" to delete the last digit (long press to clear all)
   • Time displays as HHh MMm SSs (e.g., type "130" for 1 minute 30 seconds)
2. Select a bell sound from the dropdown menu (tap "Preview" to test the sound)
3. Tap "Start" to begin the interval timer
4. The countdown displays remaining time in HH:MM:SS format
5. The bell will ring at each interval and restart automatically
6. Tap "Stop" to stop the timer at any time

Project Structure

IntervalBell/
├── app/
│   ├── src/
│   │   └── main/
│   │       ├── java/com/intervalbell/app/
│   │       │   ├── MainActivity.java
│   │       │   └── BellTone.java
│   │       ├── res/
│   │       │   ├── layout/
│   │       │   │   └── activity_main.xml
│   │       │   └── values/
│   │       │       ├── strings.xml
│   │       │       ├── colors.xml
│   │       │       └── themes.xml
│   │       └── AndroidManifest.xml
│   └── build.gradle
├── build.gradle
├── settings.gradle
└── gradle.properties

Permissions

The app requires the following permissions:

• WAKE_LOCK: To keep the device awake during timer operation
• VIBRATE: To provide haptic feedback when the bell rings

Technical Details

• Language: Java
• Minimum SDK: 24 (Android 7.0)
• Target SDK: 34 (Android 14)
• UI Framework: Material Design Components
• Timer Implementation: CountDownTimer
• Audio Playback: MediaPlayer with system notification sounds

Future Enhancements

Potential improvements for future versions:

• Custom sound file support
• Multiple interval presets
• Statistics and history tracking
• Widget support for quick access
• Dark mode optimization

License

This project is open source and available for modification and distribution.