Interfacing 3.5 inch LCD to Mega2560

Projects General Guidance
1

I am not having success interfacing a 3.5 inch TFT LCD shield with a Mega2560.

I have loaded the TFT_HX8357 library which supposedly supports the ILI9481 display.
I also used #define ILI9481 in User_Setup.h

I substituted the ILI9481 for the ITDB32S in examples URTouch_Quickpaint and URTouch_ButtonTest.
and used the following commands
UTFT myGLCD(ILI9481,38,39,40,41) and URTouch myTouch(6,5,4,3,2)
I assume that these are the correct numbers?

Unfortunately all I get is a faint blue screen

Here's hoping that someone can help.

2

Please post a link to the product page, data sheet and Arduino libraries for your display,
Also post a circuit diagram of your hardware.
Then post your code, using code tags.

3

https://www.ebay.com.au/itm/3-5-Inch-TFT-Color-Sn-Module-320-X-480-Support-Arduino-UNO-Mega2560-GI/263539926933?ssPageName=STRK%3AMEBIDX%3AIT&var=562574858338&_trksid=p2057872.m2749.l2649

GitHub - Bodmer/TFT_HX8357: Arduino library for HX8357 TFT display library

Circuit diagram is simply placing this TFT shield directly on the Mega2560

I posted reference to URtouch files in the Arduino example file section but have changed to examples in the TFT_HX8357 file such as UTFT_Demo_480x320 and left this unchanged. However I did select #define ILI9481 in the User_Setup.h file.

The code is unchanged from the demo file.

4

I could not find a library reference with the shield. It may or may not work with your library.

5

Maybe I should get rid of the shield and do direct connections via voltage reduction to the Mega2560?

I did find other examples as follows in other arduino examples in files such as URTouch_Button Test under URTouch.
Should I use the code for Standard Arduino Mega/Due shield - see below?

The other thought is to throw this shield away and buy a known and well documented one???

// Initialize display
// ------------------
// Set the pins to the correct ones for your development board
// -----------------------------------------------------------
// Standard Arduino Uno/2009 Shield            : <display model>,19,18,17,16
// Standard Arduino Mega/Due shield            : <display model>,38,39,40,41
// CTE TFT LCD/SD Shield for Arduino Due       : <display model>,25,26,27,28
// Teensy 3.x TFT Test Board                   : <display model>,23,22, 3, 4
// ElecHouse TFT LCD/SD Shield for Arduino Due : <display model>,22,23,31,33
//
// Remember to change the model parameter to suit your display module!
UTFT    myGLCD(ITDB32S,38,39,40,41);

// Initialize touchscreen
// ----------------------
// Set the pins to the correct ones for your development board
// -----------------------------------------------------------
// Standard Arduino Uno/2009 Shield            : 15,10,14, 9, 8
// Standard Arduino Mega/Due shield            :  6, 5, 4, 3, 2
// CTE TFT LCD/SD Shield for Arduino Due       :  6, 5, 4, 3, 2
// Teensy 3.x TFT Test Board                   : 26,31,27,28,29
// ElecHouse TFT LCD/SD Shield for Arduino Due : 25,26,27,29,30
//
URTouch  myTouch( 6, 5, 4, 3, 2);
6

Is there a very simple example of interfacing this ILI9481 to a mega2560 as a starting point so that I can build on it?

7

The display should be plug and play on a Mega with the correct header files. Don’t start messing with discrete wires, too much can go wrong and it is totally unnecessary. Voltage translation is handled by the two larger chips on the display pc board.

Several thoughts:

  1. The display has no touch panel. You should not have/include any code that is for touch.
  2. Forget trying the utft add-ons, they are there for compatibility. Utft is its own world, don’t go there, it’s not needed or desirable.
  3. Use the example “graphicstest_320x480.ino” for testing
  4. You should be posting in the “displays” subsection of the forum, you might get guidance from the developer of the library directly.
8

Thanks Karma,

I used the example suggested by you "graphicstest_320x480.ino" and altered the User_Setup.h file so that ILI9481 display was used and commented out the others.

Everything compiled and uploaded without any problems but still a bright light blue screen.

Maybe I should post in the "displays" section but do I start from scratch there or start from about this point for this forum as I have never re-listed on a different forum?