const int LDR = A0;         // analog pin to which LDR is connected
const int LED = 13;         // pin to which LED is connected
const int sensitivity = 50; // setting the light sensitivity

int LDRValue = 0;           // variable to store LDR values
int threshold;              // light sensitivity threshold
float voltage;              // variable to store voltage

void setup()
{
  Serial.begin(9600);                         // start the serial monitor with 9600 baud
  pinMode(LED, OUTPUT);                       // configure LED pin to behave as output
  threshold = analogRead(LDR) - sensitivity;  // set light sensitivity threshold
}

void loop()
{
  LDRValue = analogRead(LDR);                 // read LDR value
  Serial.print("Raw Rate: ");                 // print text
  Serial.println(LDRValue);                   // print value to serial monitor
  float voltage = LDRValue * (5.0 / 1023.0);  // convert analog reading (which goes from 0-1023) to a voltage (0-5V)
  Serial.print("Voltage: ");
  Serial.println(voltage);
  Serial.println();

  if (LDRValue <= threshold)                  // if the LDR reading is lower than the threshold
  {
    for (int i = 0; i <= 50; i++) {           // blink LEDs
      digitalWrite(LED, HIGH);
      delay(50);
      digitalWrite(LED, LOW);
      delay(50);
    }
    delay(1000);
    threshold = analogRead(LDR) - sensitivity; // set light sensitivity threshold
    delay(1000);
  }
  else
  {
    digitalWrite(LED, LOW);
  }
}