#include <Keypad.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(13, 12, 11, 10, 9, 8);

const byte ROWS = 4;
const byte COLS = 4;

const char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

const byte rowPins[ROWS] = {7, 6, 5, 4};
const byte colPins[COLS] = {3, 2, 1, 0};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() {
  lcd.begin(16, 2);
}

void loop() {
  char key = keypad.getKey();
  if(key != NO_KEY) {
    lcd.clear();
    lcd.println(key);
  }
}