How to Use Pantalla 3.5" Táctil Resistiva SPI ILI9488 y XPT2046: Examples, Pinouts, and Specs

The Pantalla 3.5" Táctil Resistiva SPI ILI9488 y XPT2046, manufactured by TZT, is a versatile 3.5-inch resistive touchscreen display designed for embedded systems. It features the ILI9488 driver for high-quality graphics rendering and the XPT2046 controller for precise touch input detection. This display is ideal for creating interactive user interfaces in projects requiring both visual output and touch-based input.

• Embedded systems and IoT devices
• Industrial control panels
• DIY projects with microcontrollers (e.g., Arduino, Raspberry Pi)
• Portable devices with graphical user interfaces
• Educational and prototyping purposes

The display module has a 14-pin interface. Below is the pinout description:

To use the Pantalla 3.5" Táctil Resistiva SPI with an Arduino UNO, connect the pins as follows:

Below is an example of how to initialize and use the display and touchscreen with the Arduino UNO. This example uses the Adafruit_GFX, Adafruit_ILI9488, and XPT2046_Touchscreen libraries.

#include <Adafruit_GFX.h>          // Graphics library for ILI9488
#include <Adafruit_ILI9488.h>      // Driver for ILI9488
#include <XPT2046_Touchscreen.h>   // Touchscreen library for XPT2046

// Define pins for the display
#define TFT_CS   10  // Chip Select for ILI9488
#define TFT_DC   8   // Data/Command for ILI9488
#define TFT_RST  9   // Reset for ILI9488

// Define pins for the touchscreen
#define TOUCH_CS 4   // Chip Select for XPT2046
#define TOUCH_IRQ 3  // Interrupt pin for XPT2046

// Create display and touchscreen objects
Adafruit_ILI9488 tft = Adafruit_ILI9488(TFT_CS, TFT_DC, TFT_RST);
XPT2046_Touchscreen ts(TOUCH_CS, TOUCH_IRQ);

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);

  // Initialize the display
  tft.begin();
  tft.setRotation(1);  // Set display orientation
  tft.fillScreen(ILI9488_BLACK);  // Clear the screen

  // Initialize the touchscreen
  if (!ts.begin()) {
    Serial.println("Touchscreen initialization failed!");
  } else {
    Serial.println("Touchscreen initialized successfully.");
  }
}

void loop() {
  // Check if the touchscreen is being touched
  if (ts.touched()) {
    TS_Point p = ts.getPoint();  // Get touch coordinates

    // Map touch coordinates to screen dimensions
    int x = map(p.x, 200, 3800, 0, tft.width());
    int y = map(p.y, 200, 3800, 0, tft.height());

    // Draw a circle at the touch point
    tft.fillCircle(x, y, 5, ILI9488_RED);

    // Print touch coordinates to the serial monitor
    Serial.print("Touch at: ");
    Serial.print("X=");
    Serial.print(x);
    Serial.print(", Y=");
    Serial.println(y);
  }
}

1. Power Supply: Ensure the display is powered with the correct voltage (3.3V or 5V). Incorrect voltage may damage the module.
2. SPI Speed: Use a moderate SPI clock speed (e.g., 4 MHz) to ensure stable communication.
3. Touch Calibration: The touchscreen may require calibration for accurate touch detection. Adjust the map() function values in the code as needed.
4. Backlight Control: The backlight pin (LED) can be connected to a PWM pin for brightness control.

1. No Display Output:

   • Verify all connections are secure and match the pinout table.
   • Ensure the power supply voltage is correct.
   • Check if the Adafruit_ILI9488 library is properly installed.

2. Touchscreen Not Responding:

   • Confirm the XPT2046_Touchscreen library is installed.
   • Check the T_CS and T_IRQ connections.
   • Ensure the touchscreen is not physically damaged.

3. Incorrect Touch Coordinates:

   • Adjust the map() function values in the code to calibrate the touchscreen.
   • Ensure the display orientation (setRotation()) matches the touch mapping.

• Use a multimeter to check for continuity and proper voltage levels.
• Test the display and touchscreen separately to isolate issues.
• Refer to the library documentation for additional configuration options.

By following this documentation, you can successfully integrate the Pantalla 3.5" Táctil Resistiva SPI ILI9488 y XPT2046 into your projects and create interactive user interfaces with ease.