/*
  Photoresistor (LDR) Analog Demo

  Copyright (C) 2021 Uri Shaked.

  https://wokwi.com/arduino/projects/305193627138654786
*/


#define LDR_PIN 2

// LDR Characteristics
const float GAMMA = 0.7;
const float RL10 = 50;



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

void loop() {

  int analogValue = analogRead(A0);
  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("Room: ");
  if (lux > 50) {
    Serial.println("Light!");
  } else {
    Serial.println("Dark  ");
  }

  
  Serial.print("Lux: ");
  Serial.println(lux);


  delay(500);
}