How to Use ILI9341 2.8" TFT With Touch: Examples, Pinouts, and Specs

The ILI9341 2.8" TFT display, manufactured by Ilitek, is a versatile and compact graphical display module. It features a 240x320 pixel resolution and an integrated touchscreen interface, making it ideal for projects requiring both visual output and user interaction. This display is widely used in embedded systems, IoT devices, and DIY electronics projects due to its vibrant color rendering, touch functionality, and compatibility with popular microcontrollers like Arduino and Raspberry Pi.

• User interfaces for embedded systems
• IoT dashboards and control panels
• Portable devices with graphical displays
• Educational and DIY electronics projects
• Industrial control systems

Below are the key technical details of the ILI9341 2.8" TFT display:

The ILI9341 2.8" TFT display typically has the following pinout:

Note: Some modules may have slight variations in pin configuration. Always refer to the specific datasheet for your module.

To use the ILI9341 2.8" TFT display with an Arduino UNO, follow these steps:

1. Wiring the Display: Connect the pins of the display to the Arduino as shown below:

   ILI9341 Pin	Arduino Pin
   VCC	3.3V
   GND	GND
   CS	D10
   RESET	D9
   DC (RS)	D8
   SDI (MOSI)	D11
   SCK	D13
   LED	3.3V or 5V
   T_CS	D4
   T_CLK	D13
   T_DIN	D11
   T_DO	D12
   T_IRQ	D2

2. Install Required Libraries:

   • Install the Adafruit_GFX and Adafruit_ILI9341 libraries from the Arduino Library Manager.
   • For touch functionality, install the Adafruit_STMPE610 library (if using a resistive touchscreen).

3. Example Code: Below is an example sketch to display text and detect touch input:

   #include <Adafruit_GFX.h>       // Graphics library
   #include <Adafruit_ILI9341.h>  // ILI9341 driver library
   #include <Adafruit_STMPE610.h> // Touchscreen library
   
   // Define pins for the display
   #define TFT_CS   10
   #define TFT_DC   8
   #define TFT_RST  9
   
   // Define pins for the touchscreen
   #define TS_CS    4
   
   // Create display and touchscreen objects
   Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);
   Adafruit_STMPE610 ts = Adafruit_STMPE610(TS_CS);
   
   void setup() {
     // Initialize serial communication
     Serial.begin(9600);
   
     // Initialize the display
     tft.begin();
     tft.setRotation(1); // Landscape orientation
     tft.fillScreen(ILI9341_BLACK);
     tft.setTextColor(ILI9341_WHITE);
     tft.setTextSize(2);
     tft.println("ILI9341 TFT Display");
   
     // Initialize the touchscreen
     if (!ts.begin()) {
       Serial.println("Touchscreen not found!");
       while (1);
     }
     Serial.println("Touchscreen initialized.");
   }
   
   void loop() {
     // Check for touch input
     if (ts.touched()) {
       TS_Point p = ts.getPoint();
   
       // Map touch coordinates to screen coordinates
       int x = map(p.x, 0, 240, 0, tft.width());
       int y = map(p.y, 0, 320, 0, tft.height());
   
       // Draw a circle at the touch point
       tft.fillCircle(x, y, 5, ILI9341_RED);
   
       // Print touch coordinates to the serial monitor
       Serial.print("Touch at: ");
       Serial.print(x);
       Serial.print(", ");
       Serial.println(y);
     }
   }
   

• Ensure the display operates at 3.3V logic levels. Use a level shifter if your microcontroller operates at 5V.
• Avoid excessive current draw by limiting the backlight voltage to the recommended range.
• Use proper decoupling capacitors near the power pins to reduce noise.

1. The display does not turn on:

   • Verify the power connections (VCC and GND).
   • Ensure the backlight pin (LED) is connected to 3.3V or 5V.

2. No image on the screen:

   • Check the SPI connections (CS, DC, MOSI, SCK).
   • Ensure the Adafruit_ILI9341 library is correctly installed and initialized.

3. Touchscreen not responding:

   • Verify the touchscreen SPI connections (T_CS, T_CLK, T_DIN, T_DO).
   • Ensure the Adafruit_STMPE610 library is installed and initialized.

4. Flickering or distorted display:

   • Check for loose connections or poor soldering.
   • Ensure the power supply is stable and noise-free.

• Use a multimeter to verify voltage levels at the display pins.
• Test the display with a known working example sketch to rule out software issues.
• Consult the module's datasheet for additional details on pin configuration and operation.

By following this documentation, you can successfully integrate the ILI9341 2.8" TFT display with touch functionality into your projects.