int yellow =  9;

int red = 5;

void setup() {

​

pinMode(yellow, OUTPUT); // sets the digital pin 10 (yellow pin) as output

pinMode(red, OUTPUT); // sets the digital pin 11 (red pin) as output

}

void loop() {

​

digitalWrite(yellow, HIGH);

// waits 1.5 seconds

delay(1500);

// sets the yellow pin off

digitalWrite(yellow, LOW);

// sets the red pin on

digitalWrite(red, HIGH);

// wait for 3 seconds

delay(3000);

// sets the red pin off

digitalWrite(red, LOW);

}