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

#define I2C_ADDR    0x27
//#define LCD_COLUMNS 20
#define LCD_COLUMNS 16
//#define LCD_LINES   4
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

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] = { 5, 4, 3, 2 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 }; // Pins connected to R1, R2, R3, R4

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

volatile int ledState__ = LOW;

void isrTimer1() {
	ledState__ = ledState__ == HIGH ? LOW : HIGH;
	digitalWrite(12, ledState__);
}

void handlePressed(char kchar) {	
	switch(kchar) {
		case '*':
			lcd.scrollDisplayLeft();
			break;

		case '#':
			lcd.scrollDisplayRight();
			break;

		case 'C':
			lcd.clear();
			break;
		case 'D':
			lcd.home();
			break;

		case 'A':
			lcd.autoscroll();
			break;
		case 'B':
			lcd.rightToLeft();
			break;

		default:
			lcd.print(kchar);
	}
}

void setup() {
  Serial.begin(9600);

  //keypad.setDebounceTime(10);

  lcd.init();
  lcd.backlight();
  // Print something
  lcd.setCursor(3, 0);
  lcd.print("Hello, world!");
  lcd.setCursor(0, 1);
	lcd.cursor();
	lcd.blink();

	Timer1.initialize(1000000);
	Timer1.attachInterrupt(isrTimer1);
}

void loop() {
	if (keypad.getKeys()) {
		for (int i=0; i < LIST_MAX; ++i) {
			const char *msg = NULL;
			if (keypad.key[i].stateChanged) {
				switch (keypad.key[i].kstate) {
					case PRESSED:
						msg = "PRESSED";
						handlePressed(keypad.key[i].kchar);
						break;
					case HOLD:
						msg = "HOLD";
						break;
					case RELEASED:
						msg = "RELEASED";
					case IDLE:
						msg = "IDLE";
					default:
						msg = "ERR";
				}

				Serial.print(keypad.key[i].kchar);
				Serial.print(" ");
				Serial.print(msg);
				Serial.println();
			}
		}
	}
}