/* THIS comment program cannot compile 
 #include <LiquidCrystal.h>

const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
  uint8_t t = 65;
  lcd.begin(16, 2);
  lcd.printf("t = %d", t);
}

void loop() {
}

*/


// THIS comment program can compile & work
#include <LiquidCrystal_I2C.h> 

const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  uint8_t t = 65;
  lcd.init(); // lcd module activate 
  lcd.backlight(); // lcd backlight activate
  
  lcd.begin(16, 2); // บรรทัดนี้มีก็ได้ ไม่มีก็ได้
  lcd.printf("t = %d", t);
}

void loop() {
}

// eof program