const int LED_PIN    = 0;
const int BUTTON_PIN = 1;

// Morse timing (milliseconds)
const int DOT        = 200;
const int DASH       = DOT * 3;
const int INTRA_GAP  = DOT;          // between dots/dashes
const int LETTER_GAP = DOT * 3;      // between letters
const int WORD_GAP   = DOT * 7;      // between words

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
}

void loop() {
  if (digitalRead(BUTTON_PIN) == LOW) {
  flashSTAY();

  while (digitalRead(BUTTON_PIN) == LOW) {
    delay(10);
  }
}
}

// ---------- Morse primitives ----------

void flashDot() {
  digitalWrite(LED_PIN, HIGH);
  delay(DOT);
  digitalWrite(LED_PIN, LOW);
  delay(INTRA_GAP);
}

void flashDash() {
  digitalWrite(LED_PIN, HIGH);
  delay(DASH);
  digitalWrite(LED_PIN, LOW);
  delay(INTRA_GAP);
}

void letterGap() {
  delay(LETTER_GAP - INTRA_GAP);
}

void wordGap() {
  delay(WORD_GAP - INTRA_GAP);
}

// ---------- Letters ----------

void S() { flashDot(); flashDot(); flashDot(); letterGap(); }
void T() { flashDash(); letterGap(); }
void A() { flashDot(); flashDash(); letterGap(); }
void Y() { flashDash(); flashDot(); flashDash(); flashDash(); letterGap(); }



// ---------- Message ----------

void flashSTAY() {
  S();
  T();
  A();
  Y();
  delay(WORD_GAP);   // pause after message
}