int ldrPin = A0;
int ldrVal = 0;
int ledPin = 2;

const float GAMMA = 0.7;
const float RL10 = 50;


void setup() {
  Serial.begin(9600);
  pinMode(2, OUTPUT);
}

void loop() {
  ldrVal = analogRead(ldrPin);
  float voltage = ldrVal / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10,GAMMA)/resistance, (1/GAMMA));

  if(lux < 200){
    digitalWrite(ledPin,HIGH);

  }else {
    digitalWrite(ledPin,LOW);
  }
  Serial.println(lux);
  delay(1000);
}