TouchScreen TFT ILI 9341 SSD1289 not displaying

Other Hardware Displays
1

Hello Colleagues,

I'm working on the automation of an hydroponic system since a while.

Everything worked well before I wanted to use a TFT touchscreen

Before, I used a TFT ILI9486 directly connected to the Arduino Mega without shield and it was working fine.

With my new arrival, the touchscreen ILI9341 SSD128 https://www.aliexpress.com/store/product/LCD-3-2-inch-TFT-Touch-Screen-Module-Display-Ultra-HD-320-240-ILI9341-Compatible-Punctuality/1326062_32548227874.html?spm=2114.12010615.8148356.8.1ea3d7aaEB4gpn

I have many difficulties. Even before going to the touch functionnalities, I cannot even display anything. Whitescreen (only LED working).

I use the UTFT library, and pinned right all the DB connections, RS, WR , RD, CS and Reset regarding the requirement of the library UTFT - Rinky-Dink Electronics

Unfortunately nothing works. >:(

I know some screen only works on 3,3V which does not fit directly to the Arduino Mega.
But my previous screen worked well without shields, and I saw some projects with ILI9341 used without shield too.
I am also afraid that if I find a shield, maybe the pins won't fit with the pins of the screen, since all screens do not have the pins in the same order ( DB0 - DB08 , DB-09-DB15,...)
Anyway If there is a possibility to avoid an additional shield or waiting an other 2 months for recepetion I would do it.

Regarding of the description of the product, they say it is compatible to 5V, so normally there would be a solution without shield.

I try to find solutions by myself or on forum, but this time I totally blocked, any help would be lovely :smiley:

Thanks guys !

2

Why all the TFT touchscreen never come with their appropriate shield ? :frowning:
Can't find any on aliexpress, not sure if all shields fit too all TFT touchscreen, different pins at different positions.

Maybe a SPI connection but I'm not sure that this display would be able to do it and also my code is already quite heavy, I know that SPI can slow down the Arduino

3

bogtus:
I know some screen only works on 3,3V which does not fit directly to the Arduino Mega.
But my previous screen worked well without shields, and I saw some projects with ILI9341 used without shield too.
I am also afraid that if I find a shield, maybe the pins won't fit with the pins of the screen, since all screens do not have the pins in the same order ( DB0 - DB08 , DB-09-DB15,...)
Anyway If there is a possibility to avoid an additional shield or waiting an other 2 months for recepetion I would do it.

In the days of Trump, truth does not matter anymore.

Regarding of the description of the product, they say it is compatible to 5V, so normally there would be a solution without shield.

Shops will say anything. They just want your money. They know that most customers do not complain.

You have bought a 34-pin 3.3V module. There are no level shifters on the pcb.
It will be damaged by 5V GPIO.

All that you have to do is install 21 level-shifter channels and it will work with your Mega.
alternatively, buy a 3.3V Due or STM32. Then you can wire directly.

As far as I know, there are no commercial Adapter Shields that receive your 34-pin module.
But you can make your own Adapter with a Protoshield, 34-pin socket and 21 level-shifters.

Personally, I would use a Protoshield with a Due. No level shifters.

David.

4

Thank you so much David,

So many answers in one post :smiley: I would have lost so much time.

I can't use a Due, since I need a bigger process& ram & pings for my project.

Sad that there is no shield for this Touchscreen, damn aliexpress ( second touchscreen I buy, first one was not a touch screen, second is not usable >< )

What do you think about the SPI communication, would it be possible ?

Next time I'll buy a Touchscreen directly sold with its shield, but can't find any for cheap.

Thanks again David !

5

Look at photos of the display pcb. If it has the correct number of pins in the correct places to mate with your Arduino headers, it is a Shield.

A Uno Shield will fit on Uno, Mega, Due, ... e.g. 6x1, 8x1, ...
A Mega Shield will fit on Mega or Due. e.g. 18x2 pin header.

Display Shields will be designed for 5V Uno or 5V Mega.

If you find a display with 20x2 or 17x2 or 16x2, it will not mate with the Mega 18x2.
You need an appropriate Adapter shield.

There are lots of cheap Display Shields. If unsure, post a link to the advert and ask on the Forum.

It is a lot more convenient to buy a Display Shield than to buy a module that requires an Adapter.

David.

6

I use 2.8", ILI9341 Uno shield/SD card , multi wire with my DUE.

7

Hi guys,

I'm back.

I still focus on using my Touchscreen https://www.aliexpress.com/store/product/LCD-3-2-inch-TFT-Touch-Screen-Module-Display-Ultra-HD-320-240-ILI9341-Compatible-Punctuality/1326062_32548227874.html?spm=2114.12010615.8148356.8.1ea3d7aaEB4gpn

I have this shield ( not directly compatible with my display) ; https://www.aliexpress.com/item/TFT-3-2-inch-Mega-Touch-LCD-Expansion-Board-Shield-IC-partial-pressure-for-arduino-Mega/32340683681.html?spm=a2g0s.9042311.0.0.51d94c4dXF3YC1

Would it be possible to use it in order to make the voltage conversion ?
Then I would use the shield with SPI and not parallel anymore to avoid to many wires.

Thanks again for the help.

8

Your display has a 17x2 header.
Your Adapter Shield expects 20x2 header.

Yes, you can identify each pin on your 17x2 and route it to the appropriate hole in the Adapter 20x2.

I am not going to do it for you. I suggest that you sit down with pencil and paper and draw your connections. Choose several different colours for your wires.

Then put the wiring scheme into real life.

You will have a horrible rats nest of wires. Just do everything carefully.

Think about it. For about $10 (and a long wait from China) you could buy a display shield that fits your Mega.

David.

9

I thought that in SPI it would require just a few connection to the shield ( 8?) and same amount then from the shield to the arduino.

Could you just give me your opinion on this one ?
https://www.aliexpress.com/item/3-2-inch-240x320-TFT-LCD-Touch-Screen-Display-Module-panel-with-SD-card-for-arduino/32760285116.html?spm=2114.search0104.3.76.51431a82ulD4BG&ws_ab_test=searchweb0_0,searchweb201602_3_10065_10068_318_319_10696_450_10084_10083_10618_452_535_534_10304_533_10307_10820_532_10821_10302_204_10843_10059_10884_10887_100031_320_10103_448_449,searchweb201603_60,ppcSwitch_0&algo_expid=3b4cb9dc-b9a6-4737-8fe6-870b00e91c19-11&algo_pvid=3b4cb9dc-b9a6-4737-8fe6-870b00e91c19&transAbTest=ae803_5

It is the only 3.2" display that i found with 20x2 pins. I don't know why many of them are 17x2, maybe it could be also connectable with some adjustment in the code.

Thanks again for your help :slight_smile:

10

There are several styles:

20x2. 3.3V GPIO needs a 40 pin Adapter Shield for Mega
18x2. 5V GPIO designed as a Mega2560 Shield.
17x2. 3.3V GPIO. I have NEVER seen an Adapter.
16x2. 3.3V GPIO FMSC pinout designed for STM32 hardware. ColdTears 40pin Adapter for Mega accepts this.

There are many Shields designed to plug straight into 5V Uno. (and fit Mega, Leo, Zero, Due, Nucleo, ... too)

Your link shows an obsolete TFT_320QVT. I suspect that current deliveries would be TFT_320QVT_9341.

Hey-ho. Surely it is easiest to buy a Mega Shield for a Mega. Or a Uno Shield for a Uno (fits everything else too)

The world would be a better place when all boards are 3.3V GPIO. You can use straight wires.

David.