#define red 8
#define green 7
char CH;

void setup() {
  Serial.begin(9600);
  pinMode(red, OUTPUT);
  pinMode(green, OUTPUT);

    Serial.print("please enter R to Trun the LED red and G to turn it green");
}
void loop() {
  if (Serial.available()>0)
 
    CH = Serial.read();
    if(CH=='R')
    {

      digitalWrite(red, HIGH);
      digitalWrite(green,LOW);
      delay(1000);
    }
    if( CH == 'G')
    {
    
      digitalWrite(red, LOW);
      digitalWrite(green, HIGH);
      delay(1000);
    }
}