#define LDR_PIN_digital  2
#define LDR_PIN_analog A0

void read_photoresistor();
void setup() 
{
  Serial.begin(115200);
  pinMode(LDR_PIN_digital, INPUT);
  
}

void loop() 
{
  read_photoresistor();
  
}

void read_photoresistor()
{
  if (digitalRead(LDR_PIN_digital) == LOW) 
  {
    Serial.println(" Light ");
  }
  else 
  {
    Serial.println(" Dark ");
  }
  delay(100);

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

  // Convert the analog value into lux value:
  int analogValue = analogRead(LDR_PIN_analog);
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
  Serial.print(" Light intensity: ");
  Serial.println(lux);
}