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

const byte ROWS = 1;
const byte COLS = 4;

char keys[ROWS][COLS] = {
  {'1', '2', '3', '4'}
};

byte rowPins[ROWS] = {8}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 6, 3, 2}; //connect to the column pinouts of the keypad

LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 for a 16 chars and 2 line display
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup()
{
  lcd.init();                      // initialize the lcd 
  lcd.backlight();
  lcd.setCursor(1,0);
  lcd.print("Hello, world!");
  lcd.setCursor(0,1);
  lcd.print("Ywrobot Arduino!");

  Serial.begin(9600);
}


void loop()
{
  static char key = keypad.getKey();
  
  if (key){
    Serial.println(key);
  }
}