Hi…In 4 bit mode, the have and the LCD must stay in snack match up. In the event that they lose snack match up with each other, it’ll never recuperate so the LCD will begin to see rubbish commands. The as it were way to recuperate is to re-initalize the LCD employing a uncommon 3 command sequence to urge back into sync. This is drained the code in begin() If you control cycle the LCD but not the Arduino that won’t offer assistance since the default control up mode for the LCD is 8 bit mode. So on the off chance that the library is in 4 bit mode and you control cycle as it were the LCD, the have (arduino) and the LCD will not be within the same mode (LCD in 8 bit mode, have in 4 bit mode) and the LCD will see trash commands.