Make a Morse Code Transceiver Using Arduino

/*
  This Program is for demonstration of MORSE CODE Communication
  which was use to send information secretly using codes of combinations dots .  and dashes -
  Thanks to open source community
 
*/
 
 
#define SIZE 26
const int ledPin = 8;
const int speakerPin = 12;
const int dotButton = 2;
const int dashButton = 7;
 
String morseCode = "";
String text = "";
int characterAscii = 0;
int startPos = 0, endPos = 0;
int startPos1 = 0, endPos1 = 0;
String characterCode = "";
int dashButtonState = 0;
int dotButtonState = 0;
 
 
//Array of MorseCode for letters of English Language A to Z
String letters[SIZE] = {
 
  // A to I
  ".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..",
  // J to R
  ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.",
  // S to Z
  "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."
};
 
 
void setup() {
  // put your setup code here, to run once:
  //Getting things Ready
  pinMode(ledPin, OUTPUT);
  pinMode(dotButton, INPUT);
  pinMode(dashButton, INPUT);
  Serial.begin(9600);
 
  Serial.println("*************************************************************");
  Serial.println("                    Demonstration of Morse Code              ");
  Serial.println("************************************************************* ");
  Serial.println("\nInstructions");
  Serial.println("1. First Write Your Morse code");
  Serial.println("2. When you are done  Write 1 on above input box and Press Enter or click Send Button ");
  Serial.println("3. For Space between letters write 2 and Press Enter ");
  Serial.println("4. For Space between words   write 3 and Press Enter ");
 
  Serial.println("5. Thats all Translation of Morse Code  will then be Shown ");
 
  Serial.println("\n\nEnter Your Morse Code Here  ");
}
 
 
void loop() {
  // put your main code here, to run repeatedly:
 
  while (Serial.available() > 0) {
    int ascii = Serial.read();
 
    switch (ascii) {
      case 49:  // 49 is Ascii value of 1
 
        Serial.print("\n");
        morseCode.concat('#');  // Placeing # at the end of morseCode to simplify further processing
 
        Serial.print("\nYour Morse code Translation :  ");
 
        endPos1 = morseCode.indexOf('#');
 
        while (endPos1 < morseCode.length()) {
          extractLetters(morseCode.substring(startPos1, endPos1));  // This function would extract Letter as name suggest and would convert  code to text SIMPLE!
          startPos1 = endPos1 + 1;
          if (startPos1 == morseCode.length()) {
            break;
          }
          endPos1 = morseCode.indexOf('#', startPos1);
        }
        startPos1 = 0;
        endPos1 = 0;
 
        text = "";  //  For New Translation
        morseCode = "";
        Serial.println("\n\nEnter Your Morse Code Here ");
 
 
        break;
 
      case 50:  // 50 is Ascii value of 2
 
        morseCode.concat("@");
        Serial.print("@");
        delay(200);
 
        break;
 
      case 51:  // 51 is Ascii value of 3
 
        morseCode.concat("#");
        Serial.print("#");
        delay(200);
 
        break;
    }
  }
 
  process();
}
 
void turnONLedSpeaker(int du) {
  //Turn ON LED
  digitalWrite(ledPin, HIGH);
  tone(speakerPin, 4699, du);  // tone(speakerPin, frequency, duration in milliSec)
}
 
void process() {
 
  dotButtonState = digitalRead(dotButton);
  dashButtonState = digitalRead(dashButton);
 
 
 
 
  if (dashButtonState == HIGH) {
    turnONLedSpeaker(400);
 
    morseCode.concat("-");  // Storing code in variable morseCode with the help of concatenation function
    Serial.print("-");      //Prints User entered Code
    delay(200);
  } else if (dotButtonState == HIGH) {
    turnONLedSpeaker(300);
 
    morseCode.concat(".");
    Serial.print(".");
    delay(200);
 
  } else {
    //Turn OFF LED
    digitalWrite(ledPin, LOW);
  }
}
 
char convertIntoText(String characterCode) {
  characterAscii = 65;
 
  for (int index = 0; index < SIZE; index++) {
    if (characterCode == letters[index]) {
      return characterAscii;
    }
    characterAscii++;
  }
}
 
void extractLetters(String words) {
  words.concat('@');  // Placeing @ at the end of word to simplify further processing
 
  endPos = words.indexOf('@');
 
 
  //Loop to extracting single character morse Code from string of word
  while (endPos < words.length()) {
    characterCode = words.substring(startPos, endPos);
 
    //Now CharacterCode will now convert in text
 
    text.concat(convertIntoText(characterCode));
 
    startPos = endPos + 1;
    characterCode = "";
 
    // if condition is just to terminate loop when our extracting single character code is complete thats all
    if (startPos == words.length()) {
      break;
    }
 
    endPos = words.indexOf('@', startPos);
  }
 
 
  Serial.print(text);
  Serial.print(" ");
  startPos = 0;
  endPos = 0;
  text = "";
}