3.2 TFT LCD with ILI9341 doesnt work with Arduino Mega

Other Hardware Displays
1

Hi All,
Im sorry for taking your time with similar thread, I couldnt solve my problem with reading other similar threads.

I bought this product from link; http://www.aliexpress.com/item/for-Arduino-3-2-inch-TFT-LCD-Touch-Screen-Module-Display-Ultra-HD-320X240-ILI9341-Compatible/32546709832.html

then I connected it according to connection instruction which is provided document in UTFT Library;

I tried instructions which is discussed in other threads but couldnt get result.

first I tried to use UTFT myGLCD(ILI9341_16,38,39,40,41); and UTFT myGLCD(33,38,39,40,41);which is advised by @TFTLCDCyg at the topic TFT_320QVT_9341 only white screen - Displays - Arduino Forum
no result just white screen

then tried UTFT myGLCD(SSD1289,38,39,40,41); white screen but there were some changing grey parts on screen.

I tried to change some values in UTFT.cpp according to some replies. but there is no result.

what can it be the problem. can anybody explain it step by step because I m not perfect on this topic.

Thanks.

Bilal

2

You have bought a 3.3V display. You must use an Adapter Shield to convert the MEGA2560 5V logic to the 3.3V levels that is required by your display. e.g. from ElecFreaks, Coldtears, ...

If you are using a Due, it already has 3.3V logic So you can wire it by hand if you are a masochist.
Or you buy an Adapter Shield for Due. These are only made by ColdTears.

Note that UTFT does NOT support the ILI9341 in 16-bit mode.
However TFTLCDcyg has posted a modified UTFT library. Look at this message

Note that there are some very cheap MEGA2560 Display Shields that plug directly into your MEGA2560. These have their own level-shifters so you do not need the Adapter shield.

Or you make your own Adapter cable like TFTLCDCyg's photo.

David.

3

Thank you for your quick reply David.
I already using modified library by TFTLCDCyg and make connections accordingly.

to make it clear about logic 3,3V. You mean Arduino Mega provides 5V at pins 22 to 43 which I use to connect TFT pins D0 to D15. so that it doesnt work.
if I use shield it will lover pin voltages to 3,3V and screen will work.
do I understand correctly.

Regards.

4

If you have connected it to 5V, you might have already damaged your display.
It MUST have 3.3V logic.

Seriously, a ready made shield is a lot easier e.g. 320x480 MEGA shield without Touch
Or 240x320 Uno shield

David.