Arduino & ST7789 1.3inch TFT Display

This is a short set up guide to get you going with the ST7789 display using a standard Arduino (ATMega328p). If you want to use this display with an ESP32, then there is a separate guide here.

Ignore the stickers on the breadboard: they’re from the temperature sensor network project

This display was used for the Weather Station project as well as creating an Arduino Racing game.

Hardware

This display is a 240×240 pixel, 16-bit (65k) colour TFT display with a ST7789 driver.

The “LiDAR night vision” project goes in to more detail about the colour.

The active LCD panel measures 23.4 x 23.4mm giving a pixel pitch of 0.0975mm, giving about 105pix/mm2. Decent.

The hook up is straight forward:

  • BLK (not connected)
  • DC > Arduino D7
  • RES > Arduino D8
  • SDA > Arduino D11 (SPI MOSI)
  • SCL > Arduino D13 (SPI CLK)
  • VCC > 5V (3.3V will not work reliably)
  • GND > Arduino GND

Software

As always, someone has done the donkey work for us and there are a select few libraries for this display. This example uses the ST7789_Fast library by cbm80amiga. As you guessed, it’s faster than the standard Adafruit ST7735/ST7789 library.

Both of the above libraries are built off the ever faithful Adafruit_GFX library, this means the standard drawLine(), fillRect(), etc, functions work.

Below is a basic section of code to demonstrate how to setup the display and carry out some simple tasks. 

#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Arduino_ST7789_Fast.h>

#define SCR_WD   240     // OLED display width, in pixels
#define SCR_HT   240      // OLED display height, in pixels
#define TFT_DC  7
#define TFT_RST 8

Arduino_ST7789 tft = Arduino_ST7789(TFT_DC, TFT_RST);

void setup() {
  tft.begin();
  tft.fillScreen(BLACK);      //equivalent to clear screen
  tft.setTextColor(WHITE);
}

void loop() {
  tft.setCursor(10, 0);
  tft.setTextSize(1);
  tft.print("Hello World.");

  tft.setCursor(10, 12);
  tft.setTextSize(2);
  tft.setTextColor(RED);
  tft.print("Hello World.");

  tft.drawLine(50, 50, 75, 90, GREEN);

  tft.fillRect(10, 50, 20, 20, BLUE);

  tft.fillTriangle(100 , 120, 150, 150, 90, 200, YELLOW);

  while (1);
}

The colour palate is defined in the library’s .h header file. The defaults are as follows:

#define	BLACK   0x0000
#define	BLUE    0x001F
#define	RED     0xF800
#define	GREEN   0x07E0
#define CYAN    0x07FF
#define MAGENTA 0xF81F
#define YELLOW  0xFFE0
#define WHITE   0xFFFF

There is also the ability to convert RGB:

#define	GREY  RGBto565(128,128,128)
#define	LGREY RGBto565(160,160,160)
#define	DGREY RGBto565( 80, 80, 80)
#define	LBLUE RGBto565(100,100,255)
#define	DBLUE RGBto565(  0,  0,128)

Fin.

Page created: 04/06/2024