int LED = 12;	            // tell Arduino that pin 12 is going to be called “LED” for the following sketch

void setup() {
pinMode(LED, OUTPUT);	    // initialize digital pin 12 as an output.
}

void loop() {	            // the loop function runs over and over again forever
digitalWrite(LED, HIGH);	// turn the LED on (HIGH is the voltage level)
delay(1000);	            // wait for a second
digitalWrite(LED, LOW);	  // turn the LED off by making the voltage LOW
delay(1000);	            // wait for a second
}