#include "Arduino.h"
#include <LiquidCrystal.h>
#define UVPIN  A2
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup()
{
  lcd.begin(16,2);
  Serial.begin(9600);
  pinMode(UVPIN, INPUT);
}

void UV_sensor(void)
{
  float sensorValue;
  float sum=0;
  float indexUV = 0;
  for(int i=0; i<1024; i++)
  {
      sensorValue=analogRead(UVPIN);
      sum=sensorValue+sum;
      delay(1);
  }
  float meanVal = sum/1024;
  indexUV = -((meanVal*1000)/(4.3*-83))/21;
  Serial.print("UV index : ");
  Serial.print(indexUV);
  Serial.print("\n");
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("UV index : ");
  lcd.setCursor(11, 0);
  lcd.print(indexUV);
  delay(20);
}

void loop()
{
  UV_sensor();
}