Controlling LED with a Relay

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin 12 as an output.
  pinMode(12, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(12, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(20000);                       // wait for 20 seconds
  digitalWrite(12, LOW);    // turn the LED off by making the voltage LOW
  delay(20000);                       // wait for 20 seconds
}

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin 12 as an output.
  pinMode(12, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(12, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(20000);                       // wait for 20 seconds
  digitalWrite(12, LOW);    // turn the LED off by making the voltage LOW
  delay(20000);                       // wait for 20 seconds
}