2.4 inch TFT LCD touch screen color screen module can be directly plugged into UNO MEGA2560 ST7789 Driver (With highlights)

Pinout & Interface Guide

The shield is designed to stack directly onto your Arduino. However, because different manufacturers sometimes use varied pin configurations, it is critical to verify the connections on the back of your specific board.

Standard Interface Pinout (Most Common Configuration)

⚠️ Important Warning for MEGA 2560 Users: If you are using an Arduino Mega 2560, the SPI pins are located on different pins than the Uno. The shield uses the ICSP header (the 2×3 pin header near the processor) for SPI communication. On the Mega, make sure the shield is aligned so these pins make contact, or ensure your library defines the correct pins (SCK=52, MOSI=51, MISO=50).

Usage Guide

Hardware Setup (Plug-and-Play)

1. Mount the Shield: Ensure your Arduino is unpowered (USB disconnected). Carefully align the 16-pin female headers of the shield with the male headers on your Arduino and press down firmly until seated evenly.

2. Insert SD Card (Optional): If you plan to display images from storage, insert a FAT16/FAT32 formatted microSD card into the slot on the back of the shield.

3. Connect Power: Connect your Arduino to your computer via USB. The shield will draw power from the 5V pin.

Software Setup (Arduino IDE)

You need two libraries to drive the display: a core graphics library and a hardware-specific driver.

Option 1: Using the TFT_eSPI Library (Recommended for Performance)

The “TFT_eSPI” library by Bodmer is the most optimized and widely recommended library for these displays, though it requires editing a configuration file.

1. Install the Library: Open Arduino IDE → Sketch → Include Library → Manage Libraries. Search for “TFT_eSPI” and install it.

2. Configure the Library:

   • Navigate to your Arduino Libraries folder (usually Documents/Arduino/libraries).

   • Go into the TFT_eSPI folder and open the User_Setup_Select.h file.

   • Comment out the line that says #include <User_Setup.h>.

   • Add the line: #include <User_Setups/Setup24_ST7789.h> (This selects the pre-configured setup for ST7789 240×240 screens).

3. Edit the Pin Configuration (If necessary):

   • If you need to edit the pins, open the User_Setup.h file (or the specific setup file you selected).

   • Look for the section defining TFT_CS, TFT_DC, TFT_RST, TFT_MOSI, and TFT_SCLK.

   • Adjust the pin numbers to match your hardware if your shield’s pinout differs from the default.

Option 2: Using Adafruit Libraries (More Universal)

If you prefer a more straightforward approach:

1. Install Libraries: In the Library Manager, install “Adafruit GFX Library” and “Adafruit ST7735 and ST7789 Library” (This library supports ST7789 drivers).

Basic Test Example (Arduino Sketch)

The following code works with the Adafruit libraries. Once uploaded, the screen should display colored graphic primitives (lines, circles, text).

#include <Adafruit_GFX.h>
#include <Adafruit_ST7789.h>
#include <SPI.h>

// Define pins based on your shield's configuration (verify on the back of your board!)[citation:1][citation:4]
#define TFT_CS   10
#define TFT_RST   -1   // Set to -1 if you don't have a reset pin connected or use the Duemilanove fix
#define TFT_DC    7

// Initialize the display object
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);

void setup() {
  Serial.begin(9600);
  Serial.println("Starting Display Test");

  // Initialize the display with the correct resolution (240x320)[citation:5]
  tft.init(240, 320);
  
  // Set rotation (1 = Landscape, 0 = Portrait)[citation:5]
  tft.setRotation(1);
  
  // Fill the screen with black to clear it
  tft.fillScreen(ST77XX_BLACK);

  // Draw a Red Rectangle
  tft.fillRect(20, 20, 200, 100, ST77XX_RED);
  
  // Set text size and color, then draw text
  tft.setTextSize(2);
  tft.setTextColor(ST77XX_WHITE);
  tft.setCursor(40, 60);
  tft.print("Hello Arduino!");
}

void loop() {
  // Your code here
}

Calibrating the Touchscreen

Before using the touchscreen, you must calibrate it to map the raw ADC (Analog-to-Digital Converter) readings to the physical screen coordinates.

1. Use the XPT2046_Touchscreen library by Paul Stoffregen (installed via Library Manager).

2. Run a calibration sketch (often included as an example like calibrate.ino).

3. The program will ask you to press crosses on the screen.

4. Record the min/max X/Y raw values printed in the Serial Monitor.

5. Integrate these calibration values (e.g., TS_MINX, TS_MAXX) into your project code to convert raw touches into accurate coordinates.