String dataRX;
int R = 10;
int G = 3;
int Y = 6;
void setup() {
  Serial.begin(9600);
  pinMode(R,OUTPUT);
  pinMode(Y,OUTPUT);
  pinMode(G,OUTPUT);
}

void loop() {
  if(Serial.available()>0)
    {
      dataRX = Serial.readString();
      Serial.print(dataRX);
      dataRX.trim();
  
    if(dataRX == "R")
      {
        digitalWrite(R,HIGH);
        delay(300);
        digitalWrite(R,LOW);
        delay(300);
        digitalWrite(R,HIGH);
        delay(300);
        digitalWrite(R,LOW);
      }
    
    if(dataRX == "Y")
      {
        digitalWrite(Y,HIGH);
        delay(300);
        digitalWrite(Y,LOW);
        delay(300);
        digitalWrite(Y,HIGH);
        delay(300);
        digitalWrite(Y,LOW);
      }
    
    if(dataRX == "G")
      {
      digitalWrite(G,HIGH);
      delay(300);
      digitalWrite(G,LOW);
      delay(300);
      digitalWrite(G,HIGH);
      delay(300);
      digitalWrite(G,LOW);
      }
      dataRX=" ";
  }
}