How to Use 1.3 inch TFT Module 240×240 ST7789: Examples, Pinouts, and Specs

The 1.3 inch TFT Module 240×240 ST7789 by Adafruit (part ID: GMT130-V1.0) is a compact and vibrant display module suitable for adding a colorful and high-resolution interface to your electronics projects. This module uses a thin-film-transistor (TFT) LCD to provide a bright and clear display with a 240x240 pixel resolution. The ST7789 driver integrated into the module allows for efficient communication and control over the display using a microcontroller, such as an Arduino UNO.

• Portable instruments and wearable devices
• User interfaces for embedded systems
• Miniature video displays
• Digital clocks and thermometers
• Gaming devices and toys

• Display Size: 1.3 inches diagonal
• Resolution: 240x240 pixels
• Driver IC: ST7789
• Interface: SPI (Serial Peripheral Interface)
• Operating Voltage: 3.3V
• Logic Level Voltage: 3.3V (5V tolerant)
• Input Current: Typically 10mA (without backlight)
• Backlight Current: Typically 20mA

1. Power Connections: Connect the VCC pin to a 3.3V power supply and the GND pin to the ground.
2. SPI Communication: Connect the SCL, SDA, RES, DC, and CS pins to the corresponding SPI and control pins on your microcontroller.
3. Backlight Control: The BLK pin can be connected to a PWM output for backlight brightness control.

• Ensure that the power supply is stable and does not exceed 3.3V.
• Use a level shifter if you are interfacing with a 5V microcontroller.
• For PWM control of the backlight, ensure that the PWM frequency is within the acceptable range for the display.
• Avoid exposing the display to direct sunlight or high temperatures to prevent damage.

#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ST7789.h> // Hardware-specific library for ST7789

// Pin definitions
#define TFT_CS        10 // Chip select line for TFT display
#define TFT_RST        9 // Reset line for TFT (or connect to +3V3)
#define TFT_DC         8 // Data/command line for TFT
#define TFT_BL         7 // Backlight control pin (optional)

// Initialize Adafruit ST7789 TFT library
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);

void setup() {
  pinMode(TFT_BL, OUTPUT); // Set backlight pin to output mode
  digitalWrite(TFT_BL, HIGH); // Turn on the backlight

  tft.init(240, 240);       // Initialize display with its resolution
  tft.fillScreen(ST77XX_BLACK); // Clear the screen to black
}

void loop() {
  // Example display code
  tft.setTextColor(ST77XX_WHITE);
  tft.setTextSize(1);
  tft.setCursor(20, 20);
  tft.print("Hello, World!");
}

• Display not powering on: Check the power connections and ensure that the voltage is 3.3V.
• No image or incorrect colors: Verify that the SPI connections are correct and that the correct pins are being used.
• Dim or flickering backlight: Ensure that the BLK pin is connected properly and that the PWM signal is within the correct range.

• Double-check all connections and solder joints for any loose connections or shorts.
• Use example code and libraries provided by Adafruit to test the display functionality.
• If using PWM for backlight control, start with a low frequency and increase as needed.

Q: Can I use this display with a 5V microcontroller? A: Yes, but you will need to use a level shifter or logic level converter to protect the 3.3V logic of the display.

Q: Is it possible to use this display without an SPI interface? A: No, this display requires an SPI interface for communication with the microcontroller.

Q: How can I increase the brightness of the display? A: You can increase the brightness by providing a higher duty cycle PWM signal to the BLK pin.

Q: What library should I use for this display? A: The Adafruit_GFX and Adafruit_ST7789 libraries are recommended for interfacing with this display.

Q: Can I display images or animations on this screen? A: Yes, the display is capable of showing images and animations. You will need to use the Adafruit_GFX library functions to draw images and update the display accordingly.