// Simple LED Blink for Arduino Uno

int ledPin = 13;  // LED connected to digital pin 13

void setup() {
  pinMode(ledPin, OUTPUT); // Set pin 13 as output
}

void loop() {
  digitalWrite(ledPin, HIGH); // Turn the LED ON
  delay(1000);                // Wait for 1 second (1000 ms)
  digitalWrite(ledPin, LOW);  // Turn the LED OFF
  delay(1000);                // Wait for 1 second
}