Build a Morse Code Transmitter with Arduino – Easy DIY Guide

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About this project

IDEA Description

We all communicate with each other through our natural Sensors (tongue, Gesture...etc). The Exciting part starts when you want to share secret information to someone. Question is How to do it ?

So the answer lies in how you transmit information in such a way that even if a third Person looks at message he won't be able to understand Until and Unless he finds a key. For this purpose I used Morse Code Communication you can also use another way to accomplish this task.

What is Morse Code ?

Morse Code is a way of communication to pass information which is done by representing original letters to combination of dot. and dashes - Like A ->.- and B-> -...

For more information on Morse code click the link below

http://wrvmuseum.org/morsecodehistory.htm

Why I Choose Morse Code ?

The Reason is Simple recently I watched a movie in which agent was passing information by clicking a button and at the receiving end other people were disclosing it. So I thought to make this with using Arduino and simple basic components.

How this Project Works ?

It is very Simple When you done making circuit on breadboard and uploaded Sketch. Click Serial Monitor and you will see it like below image

Follow the instructions and You are Ready to go

If you have any confusion Simply watch the demonstration video

Code

• Morse Code Source CODE

Morse Code Source CODEC/C++

/*
  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

  By Jalal Mansoori
*/


#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()
{
  //Turn ON LED
  digitalWrite(ledPin, HIGH);
  tone(speakerPin, 4699, 300); // tone(speakerPin, frequency, duration in milliSec)
 
}

void process()
{
  
  dotButtonState=digitalRead(dotButton);
dashButtonState=digitalRead(dashButton);




  if(dashButtonState == HIGH)
  {
    turnONLedSpeaker();
   
    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();
  
   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="";    
  
}

Schematics