#include <LiquidCrystal.h>

const int rs = 12;
const int en = 11;
const int d4 = 5;
const int d5 = 4;
const int d6 = 3;
const int d7 = 2;

const int LDRPin = A0;
const int redled = 7;
const int greenled = 6;
const int Buzzer = 13;

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {

  pinMode(redled,OUTPUT);
  pinMode(greenled,OUTPUT);
  pinMode(LDRPin,INPUT);
  pinMode(Buzzer,OUTPUT);

  lcd.begin(16,2);

  lcd.print("Voltage value:");
}

void loop() {
  int ldrValue = analogRead(LDRPin);
  float voltage = ldrValue * (5.0 / 1023.0);

  lcd.setCursor(0,1);
  lcd.print(voltage);

  delay(100);

  if(ldrValue < 900){
    digitalWrite(greenled,HIGH);
    digitalWrite(redled,LOW);
    noTone(Buzzer);
  }

  else{
    digitalWrite(greenled,LOW);
    digitalWrite(redled,HIGH);
    tone(Buzzer,1000);
    delay(1000);
    noTone(Buzzer);
    delay(1000);
  }

  

}