How to Create a Morse Code Converter Android App? (original) (raw)
Last Updated : 15 Jul, 2025
**Morse code is a way in which one can encode characters and text using dots and dashes. The international Morse codes contain 26 letters of the alphabet and some non-English letters that are Arabic numerals as well as some punctuation. In Morse code, there is no difference between the upper and lower case letters. The transmission of the Morse Code is measured in dot durations.
**The Morse Code Converter App is an app that is used to convert the given statements to Morse Code. This is done by using Android Studio. So in this article lets create a Morse Code Converter Android App using Java/Kotlin language. This project also involves the conversion of the Morse Code into relevant Statements. It means both encoding and decoding can be done using this Android app.
Steps to Implement Morse Code Convertor
Step 1: Create a New Project
To create a new project in Android Studio please refer How to Create/Start a New Project in Android Studio.
Step 2: Working with activity_main.xml file
Create 2 EditTexts in the xml file. One for writing the input and the other one for displaying the output. EditTexts are used because on clicking on the EditTexts the text can be selected and copied which will be very useful in sending the coded/uncoded message some other person using any messaging app. Make 3 Buttons: Encode, Decode and Clear.
The **Encode Button will take the input as text from the input EditText and then encode it into morse code and display it in the output EditText. The **Decode Button will take the morse code as input from the input EditText and then decode it into alphabets and numbers and display it in the output EditText. The **Clear Button will clear the input and output EditTexts.
**activity_main.xml:
activity_main.xml `
<EditText
android:id="@+id/inputEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="@style/Widget.Material3.TextInputEditText.OutlinedBox"
android:hint="Enter the text to be encoded"
android:gravity="start" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:gravity="center"
android:orientation="horizontal">
<Button
android:id="@+id/encode"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="Encode"
android:textColor="#fff"
android:textSize="16sp"/>
<Button
android:id="@+id/clear"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginStart="16dp"
android:layout_marginEnd="16dp"
android:text="Clear"
android:textSize="16sp" />
<Button
android:id="@+id/decode"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="Decode"
android:textColor="#fff"
android:textSize="16sp" />
</LinearLayout>
<EditText
android:id="@+id/outputEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="@style/Widget.Material3.TextInputEditText.OutlinedBox"
android:layout_marginTop="10dp"
android:hint="Output"
android:gravity="start" />`
**Design UI:
Step 4: Working with MainActivity file
In this file we will be fetching all UI elements using **findViewById(). Then, create a map that corresponds every letter and number to their morse codes. Now, create a reverse map which maps all the morse codes to their corresponding letters and numbers.
Create three functions for encode, decode and clearing all fields. In the encode and decode function we will mapping the user input letter by letter and display the output to their corresponding morse codes and vice versa.
**MainActivity File:
MainActivity.java `
package org.geeksforgeeks.demo;
import android.os.Bundle; import android.widget.Button; import android.widget.EditText; import androidx.appcompat.app.AppCompatActivity; import java.util.HashMap; import java.util.Map;
public class MainActivity extends AppCompatActivity { private EditText inputEditText, outputEditText; private Button encodeButton, decodeButton, clearButton;
// Map letters and numbers to Morse code
private final Map<Character, String> morseMap = new HashMap<>();
private final Map<String, Character> reverseMorseMap = new HashMap<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
inputEditText = findViewById(R.id.inputEditText);
outputEditText = findViewById(R.id.outputEditText);
encodeButton = findViewById(R.id.encode);
decodeButton = findViewById(R.id.decode);
clearButton = findViewById(R.id.clear);
initializeMorseCodeMaps();
encodeButton.setOnClickListener(v -> encodeText());
decodeButton.setOnClickListener(v -> decodeText());
clearButton.setOnClickListener(v -> clearText());
}
private void initializeMorseCodeMaps() {
// Populate Morse Code Map
String[] letters = {
".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---",
"-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-",
"..-", "...-", ".--", "-..-", "-.--", "--.."
};
String[] numbers = {
"-----", ".----", "..---", "...--", "....-", ".....",
"-....", "--...", "---..", "----."
};
// Add Letters
for (int i = 0; i < 26; i++) {
char letter = (char) ('A' + i);
morseMap.put(letter, letters[i]);
reverseMorseMap.put(letters[i], letter);
}
// Add Numbers
for (int i = 0; i < 10; i++) {
char number = (char) ('0' + i);
morseMap.put(number, numbers[i]);
reverseMorseMap.put(numbers[i], number);
}
// Add Space as "/"
morseMap.put(' ', "/");
reverseMorseMap.put("/", ' ');
}
// Convert input text to Morse code
private void encodeText() {
String inputText = inputEditText.getText().toString().toUpperCase();
StringBuilder encodedText = new StringBuilder();
for (char c : inputText.toCharArray()) {
if (morseMap.containsKey(c)) {
encodedText.append(morseMap.get(c)).append(" ");
}
}
outputEditText.setText(encodedText.toString().trim());
}
// Convert Morse code back to normal text
private void decodeText() {
String inputText = inputEditText.getText().toString().trim();
StringBuilder decodedText = new StringBuilder();
for (String morse : inputText.split(" ")) {
if (reverseMorseMap.containsKey(morse)) {
decodedText.append(reverseMorseMap.get(morse));
}
}
outputEditText.setText(decodedText.toString());
}
// Clear both text fields
private void clearText() {
inputEditText.setText("");
outputEditText.setText("");
}}
MainActivity.kt
package org.geeksforgeeks.demo
import android.os.Bundle import android.widget.Button import android.widget.EditText import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
private lateinit var inputEditText: EditText
private lateinit var outputEditText: EditText
private lateinit var encodeButton: Button
private lateinit var decodeButton: Button
private lateinit var clearButton: Button
// map letters and numbers to morse codes
private val map = mapOf(
'A' to ".-", 'B' to "-...", 'C' to "-.-.", 'D' to "-..", 'E' to ".",
'F' to "..-.", 'G' to "--.", 'H' to "....", 'I' to "..", 'J' to ".---",
'K' to "-.-", 'L' to ".-..", 'M' to "--", 'N' to "-.", 'O' to "---",
'P' to ".--.", 'Q' to "--.-", 'R' to ".-.", 'S' to "...", 'T' to "-",
'U' to "..-", 'V' to "...-", 'W' to ".--", 'X' to "-..-", 'Y' to "-.--",
'Z' to "--..", '0' to "-----", '1' to ".----", '2' to "..---", '3' to "...--",
'4' to "....-", '5' to ".....", '6' to "-....", '7' to "--...", '8' to "---..",
'9' to "----.", ' ' to "/"
)
// reverse map for decoding
private val reverseMap = map.entries.associate { (key, value) ->
value to key
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
inputEditText = findViewById(R.id.inputEditText)
outputEditText = findViewById(R.id.outputEditText)
encodeButton = findViewById(R.id.encode)
decodeButton = findViewById(R.id.decode)
clearButton = findViewById(R.id.clear)
encodeButton.setOnClickListener {
encodeText()
}
decodeButton.setOnClickListener {
decodeText()
}
clearButton.setOnClickListener {
clearText()
}
}
// converts the input text into Morse code
private fun encodeText() {
// get user input and convert to uppercase for consistency
val inputText = inputEditText.text.toString().uppercase()
// map letter by letter and convert to morse code
val encodedText = inputText.mapNotNull {
map[it]
}.joinToString(" ")
// display output
outputEditText.setText(encodedText)
}
// decode morse code to normal text
private fun decodeText() {
// get user input and remove extra spaces
val inputText = inputEditText.text.toString().trim()
// split Morse code by spaces (each Morse letter is separated by a space)
val decodedText = inputText.split(" ")
// convert Morse code back to letters
.mapNotNull {
reverseMap[it]
}.joinToString("")
// display output
outputEditText.setText(decodedText)
}
// clear all fields
private fun clearText() {
inputEditText.text.clear()
outputEditText.text.clear()
}}
`
**Refer to the following repo to get the entire code: Morse_Code_Convertor_Android