/* Program 5-1: Use delay() function to blink an LED */

const int LED = 13;         /* yellow LED */

void setup() {
    pinMode(LED, OUTPUT);   /* set LED pin as output */
}

void loop() {
    static int onOff = LOW;
    
    onOff = !onOff;             /* toggle the value of the variable */
    digitalWrite(LED, onOff);   /* set LED on/off by the variable */
    delay(333);                 /* delay 333 milliseconds */
}