HELP! Can't make the ILI9341 show a full screen with Arduino or ESP32

Projects General Guidance
1

I just got into micro controllers. I bought an ILI9341 TFT display on AliExpress to get familiar with the ESP32 micro controller family. I am trying to print a simple text on the LCD, but it does not show a full screen. I don't know what I did wrong.
I tried using a simulator to see if the LCD i got was the issue, but even the ILI9341 on the simulator is not rendering a full screen of display. Please help.

Here are the pictures of the issue:
ESP32 Real Board and Display:

2025-04-01 at 21.01.52_11cf2b39
2025-04-01 at 21.01.52_11cf2b391152×2560 268 KB

ESP32 Simulator:

Screenshot 2025-04-01 at 20-25-15 New ESP32 Project - Wokwi Simulator
Screenshot 2025-04-01 at 20-25-15 New ESP32 Project - Wokwi Simulator960×764 36.4 KB

Arduino UNO Simulator:

Screenshot 2025-04-01 at 20-35-16 New Arduino Uno Project - Wokwi Simulator
Screenshot 2025-04-01 at 20-35-16 New Arduino Uno Project - Wokwi Simulator960×868 41 KB

Here is the code I used:
For ESP32 (Simulator/Real Board):

#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>

#define TFT_CS    5
#define TFT_RST   4
#define TFT_DC    2
#define TFT_MOSI  23
#define TFT_SCK   18
#define TFT_MISO  19

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

void setup() {
    tft.begin();
    
    tft.setRotation(3);
    tft.fillScreen(ILI9341_WHITE);

    tft.drawRect(0, 0, tft.width(), tft.height(), ILI9341_WHITE);

    int centerX = tft.width() / 2;
    int centerY = tft.height() / 2;
    int radius = min(tft.width(), tft.height()) / 2;

    tft.fillCircle(centerX, centerY, radius, ILI9341_PURPLE);
}

void loop() {
}

For Arduino UNO (Simulator):

#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>

// Define pins
#define TFT_CS   10
#define TFT_DC   8
#define TFT_RST  9  // Optional, can be connected to Arduino reset

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

void setup() {
    tft.begin();
    tft.fillScreen(ILI9341_WHITE);
    tft.setCursor(20, 20);
    tft.setTextColor(ILI9341_BLACK);
    tft.setTextSize(2);
    tft.println("Hello, ILI9341!");
}

void loop() {
}

Please Help.

2

To me, the "snowy" part means "out of bounds," be it an array or memory.

3

Try the TFT_eSPI library on the ESP32, seems to be more commonly used than the Adafruit.

4

@obblit Tried both of your examples with an ESP32 wired as per your ESP32 (Simulator/Real Board) sketch cs-5 rst-4 dc-2 mosi - 23 sck - 18 miso -19. and they both worked fine.

The only difference I can see is that I powered my tft with 3.3v. Hard to see the pin numbers of the ESP32 in your simulation.

I drew two horizontal lines one at 0,1 and one at 0,318 just to see if the height looked right. They both looked good. My display has a wider black border along the side that has the connector and that is normal.

Your picture does not look good, possibly loose connections or bad display.

5

Turns out I made a mistake. The display is an ST7789 instead of an ILI9341. I used the TFT_eSPI library for the ILI9341, but it didn't work, so I changed the pins connection to match that of the ST7789 and changed the User_Setup.h configuration to match that of the ST7789.
It worked perfectly.
Thank you so much.

6

Thank you so much.
This helped me a lot.
Turns out I made a mistake. The display is an ST7789 instead of an ILI9341. I found that out by trying the TFT_eSPI library.
I change the configuration and pin connection that of the ST7789 and it worked.

Thank you.

7

those are your problems... if it were bad.. lol

8

I made a mistake. Sorry. The screen was an ST7789.
I didn't even know that black border is a normal thing. I thought it was an error on the code.

Thank you so much.

9

no problem, I'm glad you were able to figure it out.

10

So sorry guys. It was a mistake on my part. The display is an ST7789 not an ILI9341.
I used the TFT_eSPI library and set the configuration on the 'User_Setup.h' file to that of the ST7789, which I learnt from the video on this link tutorial video.
The display works well.

As for the simulator, I did not know that a black border at the bottom of the screen is a normal thing.

Thank you so much for the help.

Image 2025-04-02 at 15.07.18_e30f5dd8
Image 2025-04-02 at 15.07.18_e30f5dd81152×2560 248 KB

11

LOL. Well... what to do... Have to work with what you've got.

The problem has been fixed. It was my mistake.
Thanks a lot.

12

haha no problem! I guess you do have to do what you have to do! but I would recommend digikey cause they have like... EVERYTHING!

13

just one hour ago on an other topic opened by yourself I recommended you Displays from AliExpress. It seemed like you have no idea what they are and where to buy. I wonder if you already bought one and tried it to say they are bad.
actually I buy all my stuff on AliExpress and never had major problems with it.

15

Umm, sorry. Maybe there's a mistake somewhere. This is my first post on the forum.

Maybe it's another user with a similar username.

16

sorry, I was talking to @jonathan-carre

17

Oh. Alright then. My bad.

18

oh sorry I'm just saying I've got some stuff of aliexpress and it came in pretty bad condition!