#include <LiquidCrystal_I2C.h>
#include  <Wire.h>

LiquidCrystal_I2C lcd(0x27,  16, 2);
int r = 0;
int y = 0;
void setup() {
  pinMode(13, OUTPUT);
  lcd.init();
  lcd.backlight();
  delay(500);
}
void loop() {
//  delay (100);
//  lcd.clear();
  delay(15);
  r = analogRead(A0);
  r = map(r,0,1023,0,100);
  lcd.setCursor(0,0);
  lcd.print("Reference: ");
  lcd.setCursor(11,0);
  lcd.println(r);

  y = analogRead(A1);
  y = map(y,0,1023,0,100);
  lcd.setCursor(0,1);
  lcd.print("Actual: ");
  lcd.setCursor(11,1);
  lcd.println(y);

  int e=r-y;
  if (e > 0) {
    digitalWrite(13, HIGH);
  }
  if (e < 0) {
    digitalWrite(13, LOW);
  }
}