// Define Morse code patterns for each letter
const int dotDuration = 250; // Duration of a dot in milliseconds
const int dashDuration = 3 * dotDuration; // Duration of a dash (3 times the duration of a dot)
const int interSymbolGap = dotDuration; // Gap between symbols (same duration as a dot)
const int interLetterGap = 3 * dotDuration; // Gap between letters (3 times the duration of a dot)
const int interWordGap = 7 * dotDuration; // Gap between words (7 times the duration of a dot)
const char* morseTable[] = {
  ".-",   // 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
};

int ledPin = 15; // LED pin number
char inputChar; // Character received from the computer
const char* morsePattern; // Morse code pattern for the input character

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 bps
  pinMode(ledPin, OUTPUT); // Set LED pin as output
}

void loop() {
  if (Serial.available() > 0) { // Check if data is available on serial port
    inputChar = Serial.read(); // Read the input character
    inputChar = toupper(inputChar); // Convert input character to uppercase
    if (isalpha(inputChar)) { // Check if input is a letter
      morsePattern = morseTable[inputChar - 'A']; // Get the Morse code pattern for the input letter
      for (int i = 0; i < strlen(morsePattern); i++) { // Loop through the Morse code pattern
        if (morsePattern[i] == '.') { // If current symbol is a dot, turn on the LED for the duration of a dot
          digitalWrite(ledPin, HIGH);
          delay(dotDuration);
          digitalWrite(ledPin, LOW);
          delay(interSymbolGap);
        } else if (morsePattern[i] == '-') { // If current symbol is a dash, turn on the LED for the duration of a dash
          digitalWrite(ledPin, HIGH);
          delay(dashDuration);
          digitalWrite(ledPin, LOW);
          delay(interSymbolGap);
        }
      }
      delay(interLetterGap); // Add gap between letters
    } else if (inputChar == ' ') { // If input is a space, add gap between words
      delay(interWordGap);
    }
  }
}