#include <Keypad.h>
#include <LiquidCrystal_I2C.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' }
};

// Keypad moved to GP6-GP13 so the default I2C pins are free
uint8_t rowPins[ROWS] = { 13, 12, 11, 10 }; // Pins connected to R1, R2, R3, R4
uint8_t colPins[COLS] = { 9, 8, 7, 6 }; // Pins connected to C1, C2, C3, C4

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

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

void setup() {
  Serial.begin(115200);

  lcd.init();
  lcd.backlight();
  
  keypad.setDebounceTime(50); // Ignore bounces shorter than 50ms
  keypad.setHoldTime(200);    // Prevent accidental double-clicks

  // Print something
  lcd.setCursor(3, 0);
  lcd.print("Hello, world!");
  lcd.setCursor(2, 1);
  lcd.print("Wokwi Online IoT");
  lcd.setCursor(5, 2);
  lcd.print("Simulator");
  lcd.setCursor(7, 3);
  lcd.print("Enjoy!");
}

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

  if (key != NO_KEY) {
    Serial.println(key);
  }

  delay(1);
}