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

const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};
uint8_t colPins[COLS] = { 16, 4, 2, 15 };
uint8_t rowPins[ROWS] = { 19, 18, 5, 17 };
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Dirección I2C 0x27, pantalla 16x2

void setup() {
  Serial.begin(9600);
  lcd.init();                      // Inicializar el LCD
  lcd.backlight();                 // Encender la retroiluminación
  lcd.setCursor(0, 0);
  lcd.print("caracter: ");
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    Serial.println(key);
    lcd.setCursor(10, 0);
    lcd.print(key);
  }
}