char ch;
int redlight =  11;
int yellowlight1 = 10;
int yellowlight2 = 9;
int greenlight = 8;

void setup() {
  // put your setup code here, to run once:

  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(redlight, OUTPUT);
  pinMode(yellowlight1, OUTPUT);
  pinMode(yellowlight2, OUTPUT);
  pinMode(greenlight, OUTPUT);

  Serial.print("Press R/r,Y/y, O/o or G/g to on/off the signal for testing T/t annd all off L/l\n");
}

void loop() {
  // put your main code here, to run repeatedly:
  ch = Serial.read();

    if (ch == 'R' || ch == 'r') { 
      digitalWrite(yellowlight1, LOW);
      digitalWrite(yellowlight2, LOW);
      digitalWrite(greenlight, LOW);
      digitalWrite(redlight, HIGH);
      Serial.print("STOP\n");
    }

    if (ch == 'Y' || ch == 'y') {
      digitalWrite(redlight, LOW);
      digitalWrite(greenlight, LOW);
      digitalWrite(yellowlight1, HIGH);
      digitalWrite(yellowlight2, HIGH);
      Serial.print("WAIT\n");
    }  

    if (ch == 'G' || ch == 'g') {
      digitalWrite(redlight, LOW);
      digitalWrite(yellowlight1, LOW);
      digitalWrite(yellowlight2, LOW);
      digitalWrite(greenlight, HIGH);
      Serial.print("GO\n");
    } 

    if (ch == 'T' || ch == 't') {
      digitalWrite(redlight, HIGH);
      digitalWrite(yellowlight1, HIGH);
      digitalWrite(yellowlight2, HIGH);
      digitalWrite(greenlight, HIGH);
      Serial.print("Testing\n");
    } 

    if (ch == 'L' || ch == 'l') {
      digitalWrite(redlight, LOW);
      digitalWrite(yellowlight1, LOW);
      digitalWrite(yellowlight2, LOW);
      digitalWrite(greenlight, LOW);
      Serial.print("ALL OFF\n");
    }     

  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);

}