#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int SDA = 2;

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  pinMode(SDA, INPUT);

}

void loop() {
  int R = digitalRead(SDA);

  lcd.println(R);

}