program

const int ledPin = 13; // Pin for LED
const int buttonPin = 2; // Pin for button

const char* kinhoMorse = "-.- .. -.  .... ---"; // Morse code for my first name "KIN HO"

volatile bool ledState = false;
unsigned long previousMillis = 0;
const long dotDuration = 250; // Duration of a dot
const long dashDuration = 750; // Duration of a dash
const long spaceDuration = 1000; // Duration between characters
int morseIndex = 0; // Index for the current character in Morse code

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(buttonPin), toggleButtonState, FALLING);
}

void loop() {
  if (ledState) {
    blinkMorseCode();
  }
}

void blinkMorseCode() {
  unsigned long currentMillis = millis();

  if (kinhoMorse[morseIndex] == '\0') { // Check if we reached the end of the Morse code
    ledState = false; // Reset LED state
    digitalWrite(ledPin, LOW); // Turn off the LED
    morseIndex = 0; // Reset the Morse code index
    return;
  }

  long interval = (kinhoMorse[morseIndex] == '.') ? dotDuration :
                  (kinhoMorse[morseIndex] == '-') ? dashDuration : spaceDuration;

  if (currentMillis - previousMillis >= interval) {
    if (kinhoMorse[morseIndex] != ' ') {
      digitalWrite(ledPin, !digitalRead(ledPin)); // Toggle LED state
    }
    previousMillis = currentMillis; // Update the timing
    if (digitalRead(ledPin) == LOW || kinhoMorse[morseIndex] == ' ') {
      morseIndex++; // Move to the next Morse code character
    }
  }
}

void toggleButtonState() {
  ledState = !ledState; // Toggle the LED state
  if (!ledState) {
    digitalWrite(ledPin, LOW); // Turn off the LED immediately if the button is pressed
    morseIndex = 0; // Reset the Morse code index
  }
  previousMillis = millis(); // Reset the timing
}