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This page presents a library to use a 3,2" touch screen from 4D Systems (http://www.4dsystems.com.au/) in Australia. The screen details are :
You can import the 4D SGC library from here :
This is a library for 4DGL screens from 4D Systems in Autralia (http://www.4dsystems.com.au). Most graphic, touch and text functions are supported
Library published 07 Sep 2010 by 
Stephane ROCHON
To use it, you just have to insert the header file TFT_4DGL.h in your main.cpp and create an object using the TFT_4DGL class.
#include "mbed.h" #include "TFT_4DGL.h" TFT_4DGL my_screen (p9, p10, p11); // serial tx, serial rx, reset pin;
Even simpler, you can import this demo :
Program published 17 Oct 2010 by Stephane ROCHON
There is a modified version of this library available which corrects the following assert "*** assertion failed: 0, file serial_api.c, line 115". It can be found here:
Fixed a few minor issues in 4DGL library Moved pc serial port object used for debug output into 4DGL object itself. Previously it was a global object but its constructor wasn't getting run before the global constructor for the 4DGL object itself which led to an assert in the serial code. I also fixed a few potential buffer overruns that I saw in the code as well.
Library published 05 Jul 2011 by 
Adam Green
Forum thread discussing issue can be found here
joby antony wrote: Stephane,
Will you please let me know what is status variable doing in "status = ecran.touch_status();" I see it returns sometimes 1 , sometimes 2 or 3 . I am unable to understand. pl. help.
Thanks antony
Coming from the screen manual (p44) :
0 : No Touch Activity 1 : Touch Press 2 : Touch Release 3 : Touch Moving
The library supports all values.
So you get a 1 when you press the screen, a 2 when you remove your finger and a 3 if you move your finger while pressing the screen.
I need to spend some time to write the documentation.
Cheers,
Daniel Garden wrote: Could you post a video please :-) very interesting library
I will, I hope to find some time this week.
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Dear Stephane,
Thank you for your program and library, it allowed me to evaluate the effectiveness of mbed with a 4D TFT touch display. There are however a couple of minor points about the documentation.
It seems that you have written a wrapper around the SGC commands, where the mbed is the host microcontroller. This is in contrast to GFX, which creates a standalone module out of the display, and 4DGL is a programming language for GFX-based displays. Please find the definitions of SGC (Serial) and GFX (4DGL) platforms below, which has come from 4D Systems:
"(SGC) Serial Platform: The (SGC) Serial-Platform modules are based on the PICASO-SGC Serial Graphics Controller chip. In this mode, the PICASO-SGC becomes the slave device controlled by an external host controller. This allows you to develop your graphics applications using the host controller’s development platform and software tools. The PICASO-SGC chip has a rich set of serial commands built inside the chip and the commands are sent from the host controller via the serial (UART) interface. All it takes is a few bytes of serial data from the host controller and you can quickly and easily draw lines, circles, text and even display Images as well as play Video clips.
(GFX) 4DGL Platform: The (GFX) 4DGL-Platform modules are based on the PICASO-GFX2 Graphics Controller chip. In this mode, the PICASO-GFX2 becomes a standalone device and all application code is written in 4DGL (4D Graphics Language). Don't let the name scare you off, 4DGL is an easy to learn but a powerful high level language. It allows the developer to write applications in a high level syntax similar to popular languages such as BASIC, C and Pascal and run it directly on the PICASO-GFX2 processor. The (GFX) modules are stand alone devices. It allows the user to take complete control of all available resources on the module such as the Serial Port, the graphics display and the micro-SD memory card. It provides the user complete control over the display module allowing them to offload a lot of overhead from the host processor by creating the 'work horse' objects within the display module itself.
NOTE: There is only a single PICASO chip on the module. The chip can be configured to be either a PICASO-SGC or a PICASO-GFX2 by programming the appropriate PmmC configuration file (Personality module micro Code) in to the chip. Think of it as a soft silicon where the silicon can be reconfigured via the PmmC file."
Would it be possible to please change the references from 4DGL to 4D SGC in your documentation, to avoid confusion for other users?
Thanks and regards, Anna.