#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};

uint8_t colPins[COLS] = { 5, 4, 3, 2 }; 
uint8_t rowPins[ROWS] = { 11, 10, 9, 8}; 

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);
String phrase = "";
void setup() {
  lcd.init();
  lcd.backlight();
  //Serial.begin(9600);
}

void loop() {
  char key = keypad.getKey();

  if (key != NO_KEY) {
    //Serial.println(key);
    phrase += key;  
    lcd.clear();    
    lcd.setCursor(0, 0);
    lcd.print(phrase);
        if (phrase.length() > LCD_COLUMNS) {
      lcd.setCursor(0, 1);  
      lcd.print(phrase.substring(LCD_COLUMNS, 2 * LCD_COLUMNS));  
    }

  }
}