/* Program 4-1: Write "Hello world... " to the Serial port
 */
void setup() { 
    /* initialize serial and set the Baud rate to 9600 */
    Serial.begin(9600); 
} 

void loop() {
    /* write "Hello world" to the Serial port */
    Serial.print("Hello world... ");
    /* pause for a second then repeat */
    delay(1000);
}