Help recognising 3.5" Touchscreen LCD and patching to Mega

Hi,

I’m new here and although having spent a number of hours trying to find information about this LCD I haven’t been able to find anything specific enough. Although having a shield attached including card reader it obviously won’t plug straight in to the Mega 2560 as with the mcufriend. Although the pinouts are clearly marked I have found articles, blogs and posts suggesting different ways to patch to a Mega depending on the specific example but none with this 34 pin pattern.

From what I have read it should work OK with the UTFT library if I can patch it correctly.

I bought the LCD via Aliexpress: https://www.aliexpress.com/item/Smart-Electronics-3-5-inch-TFT-Touch-Screen-LCD-Module-Display-320-480-ILI9486-with-PCB/32588583847.html?spm=a2g0s.9042311.0.0.4GYX4b

Thanks,
Martyn

You have a 3.3V module with a 34-pin header.

It should work just fine with a 3.3V Arduino like a Due.

If you want to use a 5V Mega2560, you will need to provide at least 21 level-shifters for the TFT.
And several extra level shifters for the Touch and SD.

AS far as I know, there are not any ready-made Adapter shields for the 34-pin header.

As long as you connect the correct pins with the correct 3.3V logic, the ILI9486 controller should work fine with UTFT, TFT_HX8357, (or MCUFRIEND_kbv with appropriate SPECIAL)

David.

Thanks David for the quick response. Sounds a bit of a daunting task and I might be better off looking further for a more dedicated LCD shield, especially seeing as it only cost a few euros. Otherwise maybe a Due, although I would still need to work out the correct pin connections. Are there any files within the libraries which would help in analysing this?

Martyn

Hi Martyn,

This display matches with one STM32 board I know:
STM32F407ZGT6 Development Board ARM M4 STM32F4 cortex-M4 core Board Compatibility LCD STLINK GSM SENSOR Multiple Extension

And it is supported by my GxTFT library; see
https://github.com/ZinggJM/GxTFT/blob/master/myTFTs/my_3.5_TFT_480x320_ILI9486_STM32F407ZGM4_FSMC.h

See also this post

Just in case you want to spend more money, to be able to use this display.

Jean-Marc

@Jean-Marc,

A STM32 board delivered for $17.60 looks a pretty good deal.

Especially compared to the hassle of wiring level shifters and custom Protoshield.

Is that the only board that receives the 34-pin display? i.e. female 17x2

David.

@David,

Yes, the only one I found so far.
It looks like an overkill just for a display, but with FSMC you get speed, and the boards still has lots of pins free.

@Martyn

I forgot to mention that power supply to the display can be an issue, because different displays with this pinout expect different voltages on some pins. But the details are not present in my memory.

Your 3.5" display can be connected directly. Some bigger displays need 5V on VCC.

Jean-Marc