programa que haga un ping y diga hola si el pin funciona

void setup() {
    // put your setup code here, to run once:
    pinMode(8, OUTPUT);
    pinMode(9, OUTPUT);
}

void loop() {
    // put your main code here, to run repeatedly:
    digitalWrite(8, HIGH);
    digitalWrite(9, LOW);
    delay(1000);
    digitalWrite(8, LOW);
    digitalWrite(9, HIGH);
    delay(1000);
}