int ldr_s = A0;
void setup() {
  Serial.begin(9600);
  pinMode(ldr_s, INPUT);

  // put your setup code here, to run once:

}

void loop() {
  int Sensor_v=analogRead(ldr_s);
  Serial.print("voltage : ");
  Serial.println(Sensor_v);
  if(Sensor_v < 500)
  {
    digitalWrite(6, HIGH);

  }
  else{
    digitalWrite(6, LOW);
  }
  delay(2000);
  // put your main code here, to run repeatedly:

}