ESP32 + ST7789 (2) - TFT_eSPI 설정

스윗포테이토·2022년 10월 12일

[SPEC]
MCU - LOLIN D32 Pro
LCD - DFR0649 (driver: ST7789)

TFT_eSPI

지난 글에서 세가지 라이브러리를 언급했었는데, 최종적으로 TFT_eSPI를 사용하기로 했다. 주된 이유는 소스코드를 뜯어보기가 가장 쉬워서이다. stand-alone library라서 깃허브에서 TFT_eSPI.cpp 파일에 모든 함수가 정의되어 있기 때문에 내부 구조를 살펴보기가 용이하다.

setting

아두이노 IDE Library Manager를 통해 설치가 가능하다.
상단바에서 [Tools] > [Manage Libraries...]에서 TFT_eSPI를 설치하여 사용할 수 있다.

install

void TFT_eSPI::drawBitmap(int16_t x, int16_t y, const uint8_t *bitmap, int16_t w, int16_t h, uint16_t color)
{
  //begin_tft_write();          // Sprite class can use this function, avoiding begin_tft_write()
  inTransaction = true;

  int32_t i, j, byteWidth = (w + 7) / 8;

  for (j = 0; j < h; j++) {
    for (i = 0; i < w; i++ ) {
      if (pgm_read_byte(bitmap + j * byteWidth + i / 8) & (128 >> (i & 7))) {
        drawPixel(x + i, y + j, color);
      }
    }
  }

  inTransaction = lockTransaction;
  end_tft_write();              // Does nothing if Sprite class uses this function
}

IDE를 통해 설치한 라이브러리는 Arduino IDE의 기본 폴더 내 libraries 폴더에 저장된다. 설치할 때 default값으로 했다면 ~/Documents/Arduino/libraries/TFT_eSPI이다.

기본폴더 위치는 [Preferences] > Sketchbook Location에서 확인 가능하다.

User_Setup.h 설정

TFT_eSPI 라이브러리를 사용하기 위해서는 사용하는 MCU와 디스플레이 스펙에 맞게 User_SetUp.h파일을 수정해주어야 한다.

cd ~/Documents/Arduino/libraries/TFT_eSPI
code User_Setup.h

User_Setup.h 파일 자체에 가이드가 잘 되어 있어서 천천히 읽으면서 필요한 부분을 주석해제하고, 핀 번호 정도만 수정해서 쓸 수 있다.

ESP 32 + ST7789 + display size 240x240

#define USER_SETUP_INFO "User_Setup"

// ##################################################################################
//
// Section 1. Call up the right driver file and any options for it
//
// ##################################################################################

#define ST7789_DRIVER      // Full configuration option, define additional parameters below for this display

// For ST7789, ST7735, ILI9163 and GC9A01 ONLY, define the pixel width and height in portrait orientation

#define TFT_WIDTH 240  // ST7789 240 x 240 and 240 x 320
#define TFT_HEIGHT 240  // ST7789 240 x 240

// ##################################################################################
//
// Section 2. Define the pins that are used to interface with the display here
//
// ##################################################################################

// ###### EDIT THE PIN NUMBERS IN THE LINES FOLLOWING TO SUIT YOUR ESP32 SETUP   ######

// For ESP32 Dev board (only tested with ILI9341 display)
// The hardware SPI can be mapped to any pins

#define TFT_MISO 19
#define TFT_MOSI 23
#define TFT_SCLK 18
#define TFT_CS 14   // Chip select control pin
#define TFT_DC 32   // Data Command control pin
#define TFT_RST 15  // Reset pin (could connect to RST pin)
//#define TFT_RST  -1  // Set TFT_RST to -1 if display RESET is connected to ESP32 board RST

// ##################################################################################
//
// Section 3. Define the fonts that are to be used here
//
// ##################################################################################

// Comment out the #defines below with // to stop that font being loaded
// The ESP8366 and ESP32 have plenty of memory so commenting out fonts is not
// normally necessary. If all fonts are loaded the extra FLASH space required is
// about 17Kbytes. To save FLASH space only enable the fonts you need!

#define LOAD_GLCD   // Font 1. Original Adafruit 8 pixel font needs ~1820 bytes in FLASH
#define LOAD_FONT2  // Font 2. Small 16 pixel high font, needs ~3534 bytes in FLASH, 96 characters
#define LOAD_FONT4  // Font 4. Medium 26 pixel high font, needs ~5848 bytes in FLASH, 96 characters
#define LOAD_FONT6  // Font 6. Large 48 pixel font, needs ~2666 bytes in FLASH, only characters 1234567890:-.apm
#define LOAD_FONT7  // Font 7. 7 segment 48 pixel font, needs ~2438 bytes in FLASH, only characters 1234567890:-.
#define LOAD_FONT8  // Font 8. Large 75 pixel font needs ~3256 bytes in FLASH, only characters 1234567890:-.
//#define LOAD_FONT8N // Font 8. Alternative to Font 8 above, slightly narrower, so 3 digits fit a 160 pixel TFT
#define LOAD_GFXFF  // FreeFonts. Include access to the 48 Adafruit_GFX free fonts FF1 to FF48 and custom fonts

#define SMOOTH_FONT

// ##################################################################################
//
// Section 4. Other options
//
// ##################################################################################

#define SPI_FREQUENCY 27000000

// Optional reduced SPI frequency for reading TFT
#define SPI_READ_FREQUENCY 20000000

// The XPT2046 requires a lower SPI clock rate of 2.5MHz so we define that here:
#define SPI_TOUCH_FREQUENCY 2500000