The 2.25 inch TFT LCD ST7789 SPI display is a compact but powerful module, perfect for all kinds of embedded projects. Whether you are using an ESP32, Arduino, or Raspberry Pi, this screen allows you to display sharp, colorful graphics. In this article, we will take a closer look at the specifications, pinout, and how to use the display.
Specifications
- Size: 2.25 inch
- Resolution: 128 x 400 pixels
- Driver IC: ST7789
- Interface: SPI (4-wire)
- Supply Voltage: 3.3V
- Colors: 65K / 262K
- Viewing Angle: IPS, wide viewing angle
- Backlight: LED
Pinout
This module usually comes with a standard SPI pinout. Depending on the manufacturer, pin definitions may slightly vary, but in most cases they are as follows:
| Pin | Description |
|---|---|
| GND | Ground |
| VCC | Power 3.3V |
| SCL | SPI Clock |
| SDA | SPI MOSI (data) |
| RES | Reset |
| DC | Data/Command select |
| CS | Chip Select |
| BLK | Backlight control |
Note: Some versions do not include a CS pin, as they are designed to be used as the only device on the SPI bus.
Wiring with ESP32
An example connection between the ESP32 and the ST7789 display:
| Display | ESP32 |
| VCC | 3V3 |
| GND | GND |
| SCL | GPIO18 (SCLK) |
| SDA | GPIO23 (MOSI) |
| RES | GPIO4 |
| DC | GPIO2 |
| CS | GPIO15 |
| BLK | 3V3 or via transistor/PWM |
Software
In the Arduino IDE you can use the Adafruit ST7789 or TFT_eSPI library. These libraries make it easy to draw text, shapes, images, and even graphs.
Example code using the Adafruit ST7789 library:
#include <Adafruit_GFX.h>
#include <Adafruit_ST7789.h>
#include <SPI.h>
#define TFT_CS 15
#define TFT_RST 4
#define TFT_DC 2
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);
void setup() {
tft.init(400, 128); // resolution 400x128 (2.25 inch)
tft.fillScreen(ST77XX_BLACK);
tft.setCursor(10, 10);
tft.setTextColor(ST77XX_WHITE);
tft.setTextSize(2);
tft.println("Hello ST7789!");
}
void loop() {
}Applications
- Small user interfaces
- Sensor dashboards
- IoT projects
- Graphical representation (icons, gauges, charts)
- DIY handhelds or retro consoles
Conclusion
The 2.25 inch TFT LCD ST7789 is an excellent choice if you are looking for a compact yet colorful display. With its simple SPI interface, wide library support, and sharp IPS panel, this module is perfect for both hobby projects and professional applications.