void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
 
  pinMode(4, OUTPUT);
  Serial.begin(115200);
  
  pinMode(5, OUTPUT);
  Serial.begin(115200);
  
  pinMode(6, OUTPUT);
  

}

void loop() {
  
    Serial.begin(115200);
  Serial.println("RED LIGHT IS ON");
  digitalWrite(4, HIGH);
  digitalWrite(5, LOW);
  digitalWrite(6, LOW);
  delay(3000);

    Serial.begin(115200);
  Serial.println("YELLOW LIGHT IS ON");
  digitalWrite(4, LOW);
  digitalWrite(5, HIGH);
  digitalWrite(6, LOW);
  delay(3000);


    Serial.begin(115200);
  Serial.println("GREEN LIGHT IS ON");
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
  digitalWrite(6, HIGH);
  delay(3000);



  
}