void setup() 
{
  Serial.begin (115200);
  pinMode (13,OUTPUT);


}

void loop() 
{
  int AN0 = analogRead (A0);
  float V = AN0*5.0/1023;
  float R = 5.0*10000/V -10000;
  float lux = 12518931*pow(R,-1.405); 
  Serial.print (V);
  Serial.print (",");
  Serial.print (R);
  Serial.print (",");
  Serial.println (lux);

 if(lux > 25.0)
   digitalWrite(13,0);
 if(lux > 10.0)
   digitalWrite(13,1);
  delay(200);

}