void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(7, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(7, HIGH);
Serial.print("LED is on!\n");
delay(1000);
digitalWrite(7, LOW);
Serial.print("LED is off!\n");
delay(1000);
}