// Pin definitions
 int ledPin = 13;  // Built-in LED (or use another pin)

// Morse code timing constants (in milliseconds)
 int dotDuration = 200;      // Duration of a dot
 int dashDuration = 600;     // Duration of a dash (3x dot)
 int elementGap = 200;       // Gap between elements of same letter
 int letterGap = 600;        // Gap between letters (3x dot)
 int wordGap = 1400;         // Gap between words (7x dot)

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop() {
  blinkSOS();
  delay(3000);  // Wait 3 seconds before repeating
}

void blinkSOS() {
  // S (···)
  blinkDot(); blinkDot(); blinkDot();
  delay(letterGap);
  
  // O (−−−)
  blinkDash(); blinkDash(); blinkDash();
  delay(letterGap);
  
  // S (···)
  blinkDot(); blinkDot(); blinkDot();
  delay(wordGap);
}

// Helper functions for Morse code elements
void blinkDot() {
  digitalWrite(ledPin, HIGH);
  delay(dotDuration);
  digitalWrite(ledPin, LOW);
  delay(elementGap);
}

void blinkDash() {
  digitalWrite(ledPin, HIGH);
  delay(dashDuration);
  digitalWrite(ledPin, LOW);
  delay(elementGap);
}