How to Use Waveshare 2.4 inch 320x240 ILI9341 (Backside): Examples, Pinouts, and Specs

The Waveshare 2.4-inch 320x240 ILI9341 is a compact TFT display module designed for graphical output in embedded systems. It features a resolution of 320x240 pixels and utilizes the ILI9341 driver, which supports a wide range of microcontrollers. This display is ideal for creating graphical user interfaces (GUIs) and visualizing data in real-time. Some versions of this module also include a resistive touchscreen, enabling interactive applications.

• Embedded systems requiring graphical output
• DIY projects with microcontrollers like Arduino, Raspberry Pi, or STM32
• Portable devices with small displays
• Industrial control panels
• Educational projects for learning about displays and GUIs

The Waveshare 2.4-inch ILI9341 module has the following pinout:

1. Power Supply: Connect the VCC pin to a 3.3V power source and the GND pin to ground.
2. SPI Communication: Connect the CS, RESET, DC/RS, SDI/MOSI, and SCK pins to the corresponding SPI pins on your microcontroller.
3. Backlight Control: Connect the LED pin to 3.3V to enable the backlight. Optionally, use a PWM pin for brightness control.
4. Touchscreen (if available): If using the touchscreen version, connect the touchscreen pins (not listed above) to the appropriate ADC or GPIO pins on your microcontroller.

• Voltage Levels: Ensure all signal lines operate at 3.3V logic levels. Use level shifters if your microcontroller operates at 5V.
• SPI Speed: The ILI9341 supports SPI clock speeds up to 10 MHz. Use lower speeds for initial testing.
• Initialization: Properly initialize the ILI9341 driver in your code before sending data to the display.
• Backlight Power: Avoid connecting the LED pin directly to 5V, as it may damage the backlight.

Below is an example of how to use the Waveshare 2.4-inch ILI9341 with an Arduino UNO:

#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ILI9341.h> // ILI9341 driver library

// Define pin connections
#define TFT_CS 10   // Chip Select pin
#define TFT_DC 9    // Data/Command pin
#define TFT_RST 8   // Reset pin

// Create an instance of the display
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

void setup() {
  // Initialize the display
  tft.begin();
  
  // Set rotation (0-3)
  tft.setRotation(1);
  
  // Fill the screen with a color
  tft.fillScreen(ILI9341_BLUE);
  
  // Display text
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(10, 10);
  tft.println("Hello, ILI9341!");
}

void loop() {
  // Add your code here for dynamic updates
}

• The Adafruit_GFX and Adafruit_ILI9341 libraries must be installed in your Arduino IDE.
• Adjust the TFT_CS, TFT_DC, and TFT_RST pin definitions to match your wiring.

1. Display Not Turning On:

   • Verify the VCC and GND connections.
   • Ensure the LED pin is connected to 3.3V or a PWM pin.

2. No Output on the Screen:

   • Check the SPI connections (CS, DC/RS, SDI/MOSI, SCK).
   • Ensure the ILI9341 driver is properly initialized in your code.

3. Flickering or Distorted Display:

   • Reduce the SPI clock speed.
   • Check for loose or poor-quality connections.

4. Touchscreen Not Responding (if applicable):

   • Verify the touchscreen pins are connected correctly.
   • Calibrate the touchscreen in your code.

Q: Can I use this display with a 5V microcontroller?
A: Yes, but you must use level shifters to convert the 5V logic signals to 3.3V.

Q: What is the maximum SPI clock speed supported?
A: The ILI9341 supports SPI clock speeds up to 10 MHz.

Q: How do I control the backlight brightness?
A: Connect the LED pin to a PWM-capable pin on your microcontroller and adjust the duty cycle.

Q: Can I use this display with Raspberry Pi?
A: Yes, the ILI9341 is compatible with Raspberry Pi. Use the SPI interface and appropriate libraries like fbtft or Pillow.

Q: Is the touchscreen mandatory?
A: No, the touchscreen is optional and only available on certain versions of the module.