3.5" KMRTM35018-SPI Resistive Touch TFT (ILI9488)

[qubit999]

Hello, I got the display working, I can display text and shapes, etc.

Touch is not working as of now.

This is my touch code:

void touchDraw() {
  uint16_t x, y;
  // Check if the touch screen is pressed
  if (tft.getTouch(&x, &y)) {
    // Draw a circle at the touch position
    tft.fillCircle(x, y, 10, TFT_RED);
    Serial.print("Touch detected at: ");
    Serial.print(x);
    Serial.print(", ");
    Serial.println(y);
  }
}

I'm using touchDraw() inside my main loop(). I have no calibration code but it should react anyway somehow (not exact) if I press the touch screen anywhere, or am I wrong here? When I press the screen it doesn't jump into the if-condition, simply nothing happens. Is it possible that my touchscreen is not supported for touch?

This is my User_Setup.h:

// ================================
// Custom User_Setup.h for ILI9488 on Raspberry Pi Pico
// 3.5" 480x320 TFT (KMRTM35018-SPI)
// ================================

// ----------- DISPLAY DRIVER -----------
#define ILI9488_DRIVER              // Use ILI9488 driver

// ----------- PIN DEFINITIONS (SPI) -----------
#define TFT_MISO 16                  // SD0/MISO
#define TFT_MOSI 19                  // SDI/MOSI
#define TFT_SCLK 18                  // SCK
#define TFT_CS   17                  // CS
#define TFT_DC   22                  // D/C
#define TFT_RST  21                  // RESET
#define TFT_BL   13                  // Backlight, HIGH=on

// ----------- DISPLAY SIZE -----------
#define TFT_WIDTH  320              // ILI9488 default is portrait; width=320
#define TFT_HEIGHT 480

// ----------- SPI FREQUENCY -----------
#define SPI_FREQUENCY      20000000   // 20MHz is a safe starting point; raise if stable, lower if needed
#define SPI_READ_FREQUENCY  16000000  // Max stable read speed for ILI9488

// ----------- COLOR ORDER -----------
#define TFT_RGB_ORDER TFT_BGR         // Try TFT_RGB if colors look wrong

// ----------- FONT OPTIONS -----------
#define LOAD_GLCD   // Font 1. Original Adafruit 8 pixel font
#define LOAD_FONT2  // Font 2. Small 16 pixel high font
#define LOAD_FONT4  // Font 4. Medium 26 pixel high font
#define LOAD_FONT6  // Font 6. Large 48 pixel font
#define LOAD_FONT7  // Font 7. 7 segment 48 pixel font
#define LOAD_FONT8  // Font 8. Large 75 pixel font
#define LOAD_GFXFF  // FreeFonts. Include access to the 48 Adafruit_GFX free fonts

// ----------- TOUCH SCREEN OPTIONS -----------
#define TOUCH_CLK  18    // Shared with TFT_SCK
#define TOUCH_CS   1
#define TOUCH_DIN  19    // Shared with TFT_SDI
#define TOUCH_OUT  16    // Shared with TFT_SD0
#define TOUCH_IRQ  5
#define TOUCH_DRIVER XPT2046_DRIVER

// ----------- OTHER OPTIONS -----------
// #define SUPPORT_TRANSACTIONS         // Uncomment if using ESP/STM32 and encountering flicker (not needed for Pico)

[unsec-nl]

On this board with the 9488, you can not connect pin9 SDO(MISO) and pin13 T_DO of the display. The output pin9 SDO(MISO) does not support tristate when CS is high. Pin9 must be unconnected if other SPI devices are connected to the same SPI bus..