How to Use TFT display 1.9" 170x320: Examples, Pinouts, and Specs

The Adafruit ST7789 is a 1.9-inch thin-film transistor (TFT) display with a resolution of 170x320 pixels. It is designed for use in a wide range of electronic projects, offering vibrant colors and a crisp display for text, images, and graphics. This display is ideal for applications requiring a compact, high-quality screen, such as handheld devices, IoT projects, and user interfaces for embedded systems.

• Handheld devices and portable electronics
• IoT dashboards and smart home displays
• Wearable devices
• Embedded system user interfaces
• Educational and hobbyist projects

The Adafruit ST7789 TFT display has the following pinout:

To use the Adafruit ST7789 TFT display with an Arduino UNO, follow these steps:

1. Wiring the Display:

   • Connect the VIN pin to the 5V pin on the Arduino.
   • Connect the GND pin to the GND pin on the Arduino.
   • Connect the SCK pin to the Arduino's D13 (SPI clock).
   • Connect the MOSI pin to the Arduino's D11 (SPI data).
   • Connect the CS pin to a digital pin (e.g., D10).
   • Connect the DC pin to another digital pin (e.g., D9).
   • Connect the RST pin to another digital pin (e.g., D8).
   • Optionally, connect the BL pin to 3.3V or a PWM-capable pin for backlight control.

2. Install Required Libraries:

   • Install the Adafruit_GFX and Adafruit_ST7789 libraries from the Arduino Library Manager.

3. Example Code: Use the following example code to initialize and display graphics on the screen:

   // Include necessary libraries
   #include <Adafruit_GFX.h>    // Core graphics library
   #include <Adafruit_ST7789.h> // ST7789 driver library
   #include <SPI.h>             // SPI 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_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);
   
   void setup() {
     // Initialize serial communication for debugging
     Serial.begin(9600);
     Serial.println("TFT Display Test");
   
     // Initialize the display
     tft.init(170, 320); // Initialize with resolution 170x320
     tft.setRotation(1); // Set display orientation (1 = landscape)
   
     // Fill the screen with a color
     tft.fillScreen(ST77XX_BLACK);
   
     // Display some text
     tft.setTextColor(ST77XX_WHITE);
     tft.setTextSize(2);
     tft.setCursor(10, 10);
     tft.println("Hello, World!");
   
     // Draw a rectangle
     tft.drawRect(50, 50, 100, 50, ST77XX_RED);
   }
   
   void loop() {
     // Nothing to do here
   }
   

• Voltage Levels: Ensure the logic voltage levels match the display's requirements (3.3V). Use a level shifter if necessary.
• Backlight Control: The backlight pin (BL) can be connected to a PWM pin for brightness control.
• SPI Speed: The SPI clock speed should not exceed the display's maximum supported speed (typically 15-20 MHz).

1. No Display Output:

   • Verify all connections are secure and match the pinout.
   • Ensure the CS, DC, and RST pins are correctly defined in the code.
   • Check the power supply voltage and current.

2. Flickering or Artifacts:

   • Reduce the SPI clock speed in the code.
   • Ensure proper grounding between the Arduino and the display.

3. Backlight Not Turning On:

   • Confirm the BL pin is connected to 3.3V or a PWM pin.
   • Check for loose connections or insufficient power supply.

4. Text or Graphics Not Displaying Properly:

   • Verify the resolution and orientation settings in the code.
   • Ensure the Adafruit_GFX and Adafruit_ST7789 libraries are up to date.

• Use a multimeter to check voltage levels at the display pins.
• Test the display with example sketches from the Adafruit_ST7789 library to rule out software issues.
• If using a breadboard, ensure connections are tight and free of noise.

By following this documentation, you can successfully integrate and use the Adafruit ST7789 TFT display in your projects.