PS - it occurs to me that when you say the LCD goes dark, you may mean that the backlight lights up but all the pixels are dark. If that is the case, then the contrast pot or resistor on the 12864 needs adjusting, or you need to add an external contrast pot. Some 12864s have a contrast pot on the back of the board, others have fixed resistors, and yet others bring then pin out to the edge connector so that you can connect an external pot. I would need to see a photo of the back of the 12864 to tell which sort you have.
↧