Morse_Code.ino

const byte inPin = 4;

//letters (0-25), digits (26-36)
const byte MORSECODE [][5] = {{1,2,0,0,0}, {2,1,1,1,0}, {2,1,2,1,0}, {2,1,1,0,0}, {1,0,0,0,0}, {1,1,2,1,0}
                             ,{2,2,1,0,0}, {1,1,1,1,0}, {1,1,0,0,0} ,{1,2,2,2,0} ,{2,1,2,0,0}, {1,2,1,1,0}
                             ,{2,2,0,0,0}, {2,1,0,0,0}, {2,2,2,0,0}, {1,2,2,1,0}, {2,2,1,2,0}, {1,2,1,0,0}
                             ,{1,1,1,0,0}, {2,0,0,0,0}, {1,1,2,0,0}, {1,1,1,2,0}, {1,2,2,0,0}, {2,1,1,2,0}
                             ,{2,1,2,2,0}, {2,2,1,1,0}
                             ,{1,2,2,2,2}, {1,1,2,2,2}, {1,1,1,2,2}, {1,1,1,1,2}, {1,1,1,1,1}
                             ,{2,1,1,1,1}, {2,2,1,1,1}, {2,2,2,1,1}, {2,2,2,2,1}, {2,2,2,2,2} };

const char LETTERS [] = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','1','2','3','4','5','6','7','8','9','0'};					 
byte button = 0;
unsigned long startTime = 0;
unsigned long stopTime = 0;
unsigned long time = 0;

byte beepArray [] = {0,0,0,0,0};
byte subIndex = 0;
byte letterIndex = 0;
char letter = '0';
String str = "";

void setup(){
  Serial.begin(9600);
  
  pinMode(inPin,INPUT);
}

byte letterSearch (byte array []){
  boolean match = 0;
  for (byte index = 0; index < 36; index++ ){
    for (byte i = 0; i < 5; i++){
      match = 0;
      if (array[i] != MORSECODE[index][i]){
        break;
      }
      match = 1;
    }
    if (match) return index;
  }
  return 255;
}

void clearArray(byte array []){
  for (byte i = 0; i < 5; i++){
    array[i] = 0;
  }
}

void printArray(byte array []){
  for (byte i = 0; i < 5; i++){
    Serial.print(array[i]);
  }
  Serial.println("");
}


void loop(){
  
  startTime = millis();
  while (button == HIGH){
    button = digitalRead(inPin);
  }
  stopTime = millis();
  time = stopTime - startTime;
  
  if (time > 20 && time < 200){
    beepArray[subIndex] = 1;
    subIndex ++;
  }
  else if (time > 250){
    beepArray[subIndex] = 2;
    subIndex ++;
  }
  
  startTime = millis();
  while (button == LOW){
    button = digitalRead(inPin);
  }
  stopTime = millis();
  time = stopTime - startTime;
  
  if (time > 800){
    letterIndex = letterSearch(beepArray);
    if (letterIndex != 255){
      letter = LETTERS[letterIndex];
      str += letter;
      Serial.print(letter);
    }
    clearArray(beepArray);
    subIndex = 0;
  }
  if (time > 2000){
    str += " ";
    Serial.print(" ");
  }
}