// turn 


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(LED_BUILTIN,OUTPUT);
  Serial.println("Enter a num: ");

}

void loop() {
  // put your main code here, to run repeatedly:
  if (Serial.available() > 0){
    char c = Serial.read();
    
    if (c == '1'){
      digitalWrite(LED_BUILTIN, HIGH);
    }
    else if (c == '0'){
      digitalWrite(LED_BUILTIN, LOW);
    }
  }

}