Full Graphic Smart Controller to Mega 2560

Using Arduino Displays
4

Here is code to check your display (only). The code was tested using my clone Mega and the display wired as above. The code will print "millis() =" and the current value of millis() in the middle of the screen. If this does not work as described, try adjusting the contrast pot and check your wiring. .

#include <U8g2lib.h>

U8G2_ST7920_128X64_F_SW_SPI lcd(U8G2_R0, 23, 38, 39, U8X8_PIN_NONE);

void setup()
{
   Serial.begin(115200);
   lcd.begin();
   lcd.setFont(u8g2_font_5x7_tf);     
}

void loop()
{
   updateTime();
}

void updateTime()
{
   static unsigned long timer = 0;
   unsigned long interval = 1000;
   if (millis() - timer >= interval)
   {
      timer = millis();
      lcd.clearBuffer();
      lcd.setCursor(10, 32); 
      lcd.print("millis() = ");      
      lcd.print(millis());
      lcd.sendBuffer();
   }
}