void setup() {
  //define the pin 11 to output a digital signal
  pinMode(11, OUTPUT);
  //define the pin 6 to input a digital signal
  pinMode(6, INPUT);
}

//illumination(Lux) used to mesure the light intensity
//lower value of LUX indicate dark
//Higher value of LUX indicate light

void loop() {
  if (digitalRead(6)==LOW){ //read and check the input signal of pin 6 is low (Light)
      digitalWrite(11, LOW);  //command pin 11 to stop outputting a signal
  }
  else{                     //read and check the input signal of pin 6 is high (Dark)
      digitalWrite(11, HIGH); //command pin 11 to Start outputting a signal
  }
}