Help with touch for TFT 3.5" ILI9488 with ESP32

[MemoJimenez]

A few months ago I started working with a TFT 3.5" ILI9488 display with an integrated XPT2046 touch controller chip.

I am using an ESP32 (version 3.0.7), ARDUINO IDE (version 2.3.4) and TFT_eSPI (version 2.5.43).

So far, the library has worked correctly, and I have managed to turn on and display information on the screen, but, I have not been able to configure the touch screen. These are the pins I have defined.

SDO (MISO) — None (default 19)
SDI (MOSI) — 23
SCK — 18
CS — 15
DC — 2
RST — 4

T_CLK — 18 (connected to the same SCK pin)
T_CS — 21
T_DIN — 23 (connected to the same SDO pin)
T_DO — None as it is the same as the SDO
T_IRQ — None

Here is a picture of the back of my display for a better guide.

In my case, I have the MOSI pins disconnected, since, I have read in different forums that by doing this, the touch can work (but it didn't work yet).

I am using the following setup:
#include <User_Setups/Setup21_ILI9488.h> // Setup file for ESP32 and ILI9488 SPI bus TFT

I have tried to run the Test_Touch_Controller example, but it does not give me any data. Also, I have tried with the Keypad_480x32 example to see if the calibration data is generated, but, I have not been successful either (it only shows me the keypad, but it does not respond to the touchpad).

Thank you very much for creating this library, it would be great your help (@Bodmer).

Does anyone know what I am doing wrong or if I am missing something else to configure?

[bonillml]

I think I have the same setup as you, other than a difference in pins. What steps did you take before you your LCD to work?

Here is my Setup21_ILI9488.h:

// See SetupX_Template.h for all options available
#define USER_SETUP_ID 21

#define ILI9488_DRIVER

//#define TFT_INVERSION_OFF

#define TFT_MISO  13 // (leave TFT SDO disconnected if other SPI devices share MISO)
#define TFT_MOSI  11
#define TFT_SCLK  12
#define TFT_CS    10  // Chip select control pin
#define TFT_DC    9  // Data Command control pin
#define TFT_RST   14  // Reset pin (could connect to RST pin)


#define LOAD_GLCD   // Font 1. Original Adafruit 8 pixel font needs ~1820 bytes in FLASH
#define LOAD_FONT2  // Font 2. Small 16 pixel high font, needs ~3534 bytes in FLASH, 96 characters
#define LOAD_FONT4  // Font 4. Medium 26 pixel high font, needs ~5848 bytes in FLASH, 96 characters
#define LOAD_FONT6  // Font 6. Large 48 pixel font, needs ~2666 bytes in FLASH, only characters 1234567890:-.apm
#define LOAD_FONT7  // Font 7. 7 segment 48 pixel font, needs ~2438 bytes in FLASH, only characters 1234567890:.
#define LOAD_FONT8  // Font 8. Large 75 pixel font needs ~3256 bytes in FLASH, only characters 1234567890:-.
#define LOAD_GFXFF  // FreeFonts. Include access to the 48 Adafruit_GFX free fonts FF1 to FF48 and custom fonts

#define SMOOTH_FONT


// #define SPI_FREQUENCY  20000000
#define SPI_FREQUENCY  27000000
// #define SPI_FREQUENCY  40000000
// #define SPI_FREQUENCY  80000000

// Optional reduced SPI frequency for reading TFT
#define SPI_READ_FREQUENCY  16000000

#define SPI_TOUCH_FREQUENCY  2500000

[TangerineDreamer]

You can try this setup:

//ILI9488 & ST7796 -> ESP32

#define ILI9488_DRIVER
//#define ST7796_DRIVER

//#define TFT_INVERSION_OFF

#define TFT_MISO 19 //  -> (leave TFT SDO disconnected on the air !!! )
#define TFT_MOSI 23
#define TFT_SCLK 18
#define TFT_CS    15  // Chip select control pin
#define TFT_DC    2  // Data Command control pin
#define TFT_RST  -1//  Reset pin (could connect to RST pin)

#define TOUCH_DO 19 // -> must be connected even if MISO is on the air !!!
#define TOUCH_DIN 23 
#define TOUCH_CLK 18
#define TOUCH_CS 12//27 // Chip select pin (T_CS) of touch screen


#define LOAD_GLCD   // Font 1. Original Adafruit 8 pixel font needs ~1820 bytes in FLASH
#define LOAD_FONT2  // Font 2. Small 16 pixel high font, needs ~3534 bytes in FLASH, 96 characters
#define LOAD_FONT4  // Font 4. Medium 26 pixel high font, needs ~5848 bytes in FLASH, 96 characters
#define LOAD_FONT6  // Font 6. Large 48 pixel font, needs ~2666 bytes in FLASH, only characters 1234567890:-.apm
#define LOAD_FONT7  // Font 7. 7 segment 48 pixel font, needs ~2438 bytes in FLASH, only characters 1234567890:.
#define LOAD_FONT8  // Font 8. Large 75 pixel font needs ~3256 bytes in FLASH, only characters 1234567890:-.
#define LOAD_GFXFF  // FreeFonts. Include access to the 48 Adafruit_GFX free fonts FF1 to FF48 and custom fonts

#define SMOOTH_FONT


// #define SPI_FREQUENCY  20000000
#define SPI_FREQUENCY  27000000
// #define SPI_FREQUENCY  40000000
// #define SPI_FREQUENCY  80000000

// Optional reduced SPI frequency for reading TFT
#define SPI_READ_FREQUENCY  16000000

#define SPI_TOUCH_FREQUENCY  2500000

[solidstate90]

Where you ever able to get this working??

[TangerineDreamer]

have you tried with:
#define TFT_MISO 19 -> but nothing wired on ! (just a fake definition)
#define TOUCH_DO 19 -> this one is wired true !

[MemoJimenez]

Hello, thank you very much all for your help.

I already solved this problem, since I am using a ESP32 with 3.3V I had to make a short circuit in J1 to bypass the voltage regulator (XC6206).

Here is the reference that I found - https://nettigo.eu/products/lcd-tft-3-5-ili9488-with-touch

But if you use 5V instead, J1 has to be as a open circuit.

My setup files were working correctly, at the end it was a hardware problem.