Arduino due with 4D systems LCD

I bought the uLCD-32PTU ( and it worked fine using it as a slave with Aduino uno R3 and mega 2560, but I have problems with the Arduino due. I explain: I first loaded the Serial Library for the Picaso (GitHub - 4dsystems/Picaso-Serial-Arduino-Library: Arduino Library for 4D Systems Serial Environement for Picaso) to Aduino’s library folder then loaded this code to an arduino uno:

#include <Picaso_Serial_4DLib.h>                
#include <Picaso_Const4D.h>
#define DisplaySerial Serial
Picaso_Serial_4DLib Display(&DisplaySerial);

void setup(void){
  pinMode(2, OUTPUT);
  DisplaySerial.begin(9600) ;
  Display.TimeLimit4D = 5000 ; 
  digitalWrite(2, HIGH);
  digitalWrite(2, LOW);
  Display.gfx_Cls() ; 
  Display.putstr("Hello World\n") ;

void loop(void){


Then connected power, ground RX and TX to the arduino uno, it worked fine (see pictures 1 and 2).
Then I connected and Arduino mega uploaded the same code and it worked fine.
Then I connected an Arduino due uploaded the same code, but there is problem, there are no serial communication on the Serial port and no display on the LCD screen. I am wondering if there is a problem bettween the Serial library for the Picaso and the Arduino due… (I hope I did not make a stupid mistake, pictures 3 and 4 might help).

Thank you in advance for your help.


PS: if your webbrwoser does not show the pictures, you can find them here:

Solution found!

I showed the library to a friend and he found that a flush in the library was the problem... He says that it is a problem with the due's driver. (it's his opinion, I am not an expert)

Anyway, here is the solution: remove the flush in the Picaso_Serial_4DLib.cpp like this and it will work.

Picaso_Serial_4DLib::Picaso_Serial_4DLib(Stream * virtualPort) { 
        _virtualPort = virtualPort; 
    //_virtualPort->flush();       // PROBLEM WITH ARDUINO DUE modified by Francois 3/8/2013