#define I2C_ADDR    0x27 // <<- Trial and error, or use Arduino sketch "i2cScanner"
#define Rs_pin  0
#define Rw_pin  1
#define En_pin  2
#define BACKLIGHT_PIN 3
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

// instantiate the LCD object
LiquidCrystal_I2C lcd(I2C_ADDR, En_pin, Rw_pin, Rs_pin, D4_pin, D5_pin, D6_pin, D7_pin);