/* Program 2-3: Toggling Three pins Sequentially
 * This program uses an array to index to each LED. */

const int PINS[] = {5, 9, 10}; /* 3 pins */

void setup()
{
    /* configure pins for output */
    for (int i = 0; i < 3; i++)
    {
        pinMode(PINS[i], OUTPUT);
    }
}

void loop()
{
    /* turn PINS on one at a time */
    for (int i = 0; i < 3; i++)
    {
        digitalWrite(PINS[i], HIGH); /* turn PINS on */
        delay(500);                 /* for 500 ms */
        digitalWrite(PINS[i], LOW);  /* turn the same PINS off */
    }  
}