// Constants
#define DELAY 500 // Delay between two measurements in ms
#define VIN 5 // V power voltage
#define R 10000 //ohm resistance value

// set pin numbers:
const int buttonPin1 = 4;     // the number of the pushbutton1 pin
const int buttonPin2 = A0;     // the number of the pushbutton2 pin
const int buttonPin3 = 7;     // the number of the pushbutton3 pin
const int ledPin1 = 8;        // the number of the LED1 anode(+) pin
const int ledPin2 = 12;       // the number of the LED2 anode(+) pin

// Variables will change:
int ledState1 = LOW;         // the current state of the LED1
int ledState2 = LOW;         // the current state of the LED2
int buttonState1;             // the current reading from the input pin1
int buttonState2;             // the current reading from the input pin2
int buttonState3;             // the current reading from the input pin3
int lastButtonState1 = LOW;    // the previous reading from the input pin1
int lastButtonState2 = LOW;    // the previous reading from the input pin2
int lastButtonState3 = LOW;    // the previous reading from the input pin3


// the following variables are long's because the time, measured in microseconds,
// will quickly become a bigger number than can be stored in an int.

unsigned long lastDebounceTime = 0;   // the last time the output pin was toggled
long debounceDelay = 20000;           // the debounce time in micro second

unsigned long randNumber;                 // Generated random number
unsigned long minRandomNumber = 2000;     // minimum number used to specify the range of random number
unsigned long maxRandomNumber = 5000;     // maximum number used to specify the range of random number

unsigned long time1,time2;
int button3Pressed = LOW;
int printcount = 0;

int takeReading = LOW;

//following variable help in reading buttons pins
int reading1;
int reading2;
int reading3;

int lux;

//following variable help in reading button corresponding to perticular led i.e LED1 --> BUTTON1 and LED2 --> BUTTON2
int oddNumber ;
int evenNumber ;

void setup()
{
  pinMode(buttonPin2, INPUT);
  pinMode(ledPin1, OUTPUT);
  
  //enabling serial communication
  Serial.begin(9600);
  
  // set initial LED state
  digitalWrite(ledPin1, ledState1);

  // if analog input pin 0 is unconnected, random analog
  // noise will cause the call to randomSeed() to generate
  // different seed numbers each time the sketch runs.
  // randomSeed() will then shuffle the random function.
  randomSeed(analogRead(0));
}
    
void loop() 
{
  reading1 = analogRead(A0);
  lux=sensorRawToPhys(reading1);
  Serial.print("Raw value from sensor= ");
  Serial.println(reading1); // the analog reading
  Serial.print("Physical value from sensor = ");
  Serial.print(lux); // the analog reading
  Serial.println(" lumen"); // the analog reading

  if (lux > 50) 
  {
    digitalWrite(ledPin1, LOW);
  }
  else 
  {
    digitalWrite(ledPin1, HIGH);
  }

  delay(DELAY);
}

int sensorRawToPhys(int raw){
  // Conversion rule
  float Vout = float(raw) * (VIN / float(1023));// Conversion analog to voltage
  float RLDR = (R * (VIN - Vout))/Vout; // Conversion voltage to resistance
  int phys=500/(RLDR/1000); // Conversion resitance to lumen
  return phys;
}