Morse Code Trainer Android App with Flashlight Signals and Decoding Practice

Morse Code Trainer Android App with Flashlight Signals and Decoding Practice is an Android app that teaches International Morse Code by turning a phone into a signalling and practice station. Morse code is still used in amateur radio and emergency signalling, yet most learners meet it only as a printed chart, memorising patterns without ever hearing them at real speed. The gap is timing: a dash is three times as long as a dot, and the silences between elements, letters and words carry as much meaning as the signals, so a learner who has never practised at steady speed cannot copy even a short message. This app closes that gap by flashing messages through the phone's flashlight and speaker at standard ITU timing, with a tap key that judges press duration, and with decoding quizzes that give instant feedback. It needs no radio hardware, no partner and no internet, so practice can happen anywhere a phone goes.

The Morse Code Trainer Android app works as a closed practice loop: text goes in, Morse signals come out as light and sound, the learner sends signals back with a finger, and the app checks what was understood. A typed message is encoded with the International Morse Code table for all 36 letters and digits, under ITU timing rules: a dot lasts 1 unit, a dash 3 units, and the silences 1 unit inside a letter, 3 units between letters and 7 units between words. Playback drives the phone's flashlight and a 650 Hz tone through that sequence, so eye and ear learn one rhythm. Sending works in reverse: the tap key times each press, classifies presses under 1.5 units as dots and longer ones as dashes, and groups signals into letters after a 3-unit pause. Quizzes and word drills sit on this engine, playing letters or words, checking each answer, and recording per-letter results for the mastery view.

1. The learner types a message or picks a practice word, and the app encodes it with the International Morse Code table for all 36 letters and digits.
2. The unit length is derived from the selected speed using the standard formula of 1200 divided by WPM in milliseconds, giving 100 ms per unit at 12 WPM.
3. Playback switches the phone's flashlight on and off and sounds a 650 Hz tone, following the standard dot, dash and gap ratios exactly.
4. On the tap key, each press is timed: presses shorter than 1.5 units register as dots and longer presses as dashes, with a 3-unit pause ending each letter.
5. The decoder groups the incoming signals into letters and words and shows the decoded text live as the learner taps.
6. In quiz mode the app plays one letter at a time and the learner picks from four options, with the correct pattern shown after every answer.
7. Scores, streaks and per-letter results are saved on the phone with Room database, and the mastery view queues the weakest letters for the next session.

Tech stack:

• Kotlin
• Android SDK · Jetpack Compose
• Android Camera2 flashlight API
• Android AudioTrack tone generator
• Room database · local storage
• Material Design 3
• Android Studio
• Git

The Morse Code Trainer Android app is built around four capabilities that work together as one practice loop: a text-to-flashlight sender that plays any message as light and sound at standard ITU timing, a timing-aware tap key that turns finger presses into dots and dashes, a decoding quiz that tests recognition with instant feedback, and a word-drill mode that repeats the letters each learner misses most. Around that loop sit a full Morse chart for all 36 letters and digits, adjustable speed from 5 to 20 WPM, and progress tracking that works fully offline, so the app is a complete self-study station rather than a chart viewer with a beeper attached. The speed slider moves the unit length from 240 ms at 5 WPM to 60 ms at 20 WPM, so beginners start slow and build to realistic copying speed, while offline progress tracking records which letters still need work.

• [Text-to-flashlight sender] Type any message and the app converts it to International Morse Code, then plays it through the phone's flashlight and a 650 Hz tone at standard ITU timing, with the signal pattern shown on screen as it plays.
• [Timing-aware tap key] Press briefly for a dot and hold longer for a dash; the app measures each press against the unit length for the selected speed and decodes the letters live as you tap.
• [Decoding quiz] The app flashes and sounds a letter, then offers four options; a wrong pick immediately shows the correct pattern, and each round runs for 10 questions with a streak counter.
• [Word drills with weak-letter repetition] Target words flash first and the learner taps them back; letters answered wrongly are queued again in later rounds until they are recognised reliably.
• [Full Morse chart with audio] All 36 letters and digits are shown with their dot-dash patterns, and tapping any entry plays its pattern so the sound and the shape are learned together.
• [Adjustable speed from 5 to 20 WPM] A speed slider changes the unit length from 240 ms down to 60 ms, so beginners can start slow and work up to realistic copying speed.
• [Offline progress tracking] Session scores, streaks and per-letter mastery are stored on the phone with Room database, so progress survives app restarts and needs no account or internet connection.

• Complete Android app source code in Kotlin with Jetpack Compose UI
• Text-to-flashlight sender, timing-aware tap key, decoding quiz and word-drill modes
• Morse chart and practice word list covering all 36 letters and digits
• Working demo build of the app for the student's own phone
• Project report PDF (background, Morse timing standard, app architecture, methodology, testing)
• PPT presentation for final review
• Viva Q&A preparation document (Morse timing rules, Android flashlight and audio APIs, decoding logic)