//Set up the variable for the LED pin
int led_pin = 3;

void setup() {
  // put your setup code here, to run once:

  // initialize the LED pin as an output
  pinMode(led_pin, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(led_pin, HIGH);
  delay(1000);
  digitalWrite(led_pin, LOW);
  delay(1000);
}