void setup() {
  Serial.begin(115200); // Standard for fast serial, but not needed for just LEDs
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
}

void loop() {
  // Blink LED 1 (and keep others off)
  digitalWrite(1, HIGH); // Turn LED 1 ON
  digitalWrite(2, LOW); // Turn others OFF (Important!)
  digitalWrite(3, LOW);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
  digitalWrite(6, LOW);
  delay(500); // Blink for half a second

  // Blink LED 6 (and keep others off)
  digitalWrite(1, LOW); // Turn LED 1 OFF
  digitalWrite(6, HIGH); // Turn LED 6 ON
  digitalWrite(2, LOW); // Make sure others are OFF
  digitalWrite(3, LOW);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
  delay(500); // Blink for half a second

  // Blink LED 2 (and keep others off)
  digitalWrite(6, LOW); // Turn LED 6 OFF
  digitalWrite(2, HIGH); // Turn LED 2 ON
  digitalWrite(1, LOW); // Make sure others are OFF
  digitalWrite(3, LOW);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
  delay(500);

  // Blink LED 5 (and keep others off)
  digitalWrite(2, LOW); // Turn LED 2 OFF
  digitalWrite(5, HIGH); // Turn LED 5 ON
  digitalWrite(1, LOW); // Make sure others are OFF
  digitalWrite(3, LOW);
  digitalWrite(4, LOW);
  digitalWrite(6, LOW);
  delay(500);

  // Blink LED 3 (and keep others off)
  digitalWrite(5, LOW); // Turn LED 5 OFF
  digitalWrite(3, HIGH); // Turn LED 3 ON
  digitalWrite(1, LOW); // Make sure others are OFF
  digitalWrite(2, LOW);
  digitalWrite(4, LOW);
  digitalWrite(6, LOW);
  delay(500);

  // Blink LED 4 (and keep others off)
  digitalWrite(3, LOW); // Turn LED 3 OFF
  digitalWrite(4, HIGH); // Turn LED 4 ON
  digitalWrite(1, LOW); // Make sure others are OFF
  digitalWrite(2, LOW);
  digitalWrite(5, LOW);
  digitalWrite(6, LOW);
  delay(500);

  // Optional: Turn all off briefly before repeating
  digitalWrite(4, LOW);
  delay(200);
}