Modifyed blink

const uint8_t           pinLED      = 13;

const uint8_t           LED_OFF     = LOW;
const uint8_t           LED_ON      = HIGH;
const unsigned long     HALF_SECOND = 500UL;


void loop()
{}

void setup()
{
    pinMode(pinLED, OUTPUT);     

    digitalWrite(pinLED, LED_OFF;

    int     loop_counter = 100;
    while ( loop_counter-- )
    {
        digitalWrite(pinLED, LED_ON);
        delay(HALF_SECOND);

        digitalWrite(pinLED, LED_OFF);
        delay(HALF_SECOND);
    }
}