I was taking the advantage of an existing piece of hardware (RepRapDiscount Full Graphic Smart Controller) for my present project.
Here is a link for the RepRap wiki about the controller
#define LCD_PIN_SCLK A4 #define LCD_PIN_MOSI 6 #define LCD_PIN_CS 8 U8GLIB_ST7920_128X64_1X u8g(A4,6,8, U8G_PIN_NONE);
But all I got is a blank screen with no light at all. What has happened?