int ldr = A0;
int x = 0;
int relay = 8;
float lux=0.00;
float adc=0.0048828125;

void setup() {
  pinMode(relay, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  x = analogRead(ldr);
  lux=(250.000000/(adc*x))-50.000000;
  Serial.println(lux);
  digitalWrite(relay, HIGH);
  if (lux > 250) { 
    digitalWrite(relay, LOW);
    delay(1000); 
  } else {
    digitalWrite(relay, HIGH);
    delay(1000);
  }
  
}