I connected a Serial LCD to the Mega Shield on the Seeeduino ADK Main board. I tried to connect it to UART0 to 3 port or to any Digital ports. I tried to code it based on the examples using SerialLCD, Serial, and NewSoftSerial class. They all compiled and uploaded fine but so far the LCD does not display anything. Sometime I do see the backlight turned on or random chars displayed. But at the end, nothing worked. My board are working fine with other Grove twigs. Please help.