ESP32-C3/arduino-esp32 to display on ST7735 and ST7789 SPI LCDs

This exercise run on ESP32-C3-DevKitM-1 with arduino-esp32 2.0.0, to display on ST7735 and ST7789 SPI LCDs using "Adafruit ST7735 and ST7789 Library" and "Adafruit GFX Library".

Make sure both "Adafruit ST7735 and ST7789 Library" and "Adafruit GFX Library" are installed in Arduino IDE.

ST7735 and ST7789 share the common SPI bus and A0(DC), and separated CS and RESET. Connection refer to the exercise code, marked in RED.

ESP32C3_ST77xx_hello.ino

/*
 * arduino-esp32 exercise run on ESP32-C3-DevKitM-1,
 * display on 1.8" 128x160 TFT with SPI ST7735, and
 * 2.0" IPS 240x320 RGB LCD with SPI ST7789,
 * using 'Adafruit ST7735 and ST7789 Library'.
 * 
 * ref:
 * graphicstest example under 'Adafruit ST7735 and ST7789 Library'
 */


#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ST7735.h> // Hardware-specific library for ST7735
#include <Adafruit_ST7789.h> // Hardware-specific library for ST7789

#define TFT_CS_ST7735   10
#define TFT_RST_ST7735  9 // Or set to -1 and connect to Arduino RESET pin
#define TFT_CS_ST7789   2
#define TFT_RST_ST7789  3   
#define TFT_DC        8   

/*
 * Erik:
 * on ESP32-C3-DevKitM-1
 * SS:   7  - not used
 * MOSI: 6
 * MISO: 5  - not used
 * SCK:  4
 * ===================
 * Conection:
 * In my exercise,
 * ST7735 AND ST7789 Share the same pins, 
 * except RESET and CS, marked +
 * 
 * TFT_ST7735 ESP32-C3
 * -------------------
 * VCC        3V3
 * GND        GND
 * CS         10    +
 * RESET      9     +
 * A0(DC)     8
 * SDA        6
 * SCK        4
 * LED        3V3
 *
 * TFT_ST7789 ESP32-C3
 * -------------------
 * BLK        3V3
 * CS         2     +
 * DC         8
 * RES        3     +
 * SDA        6
 * SCL        4
 * VCC        3V3
 * GND        GND
 */

/*
 * for ST7735 displays:
 * Differences between displays (usu. identified by colored tab on
 * plastic overlay) are odd enough that we need to do this 'by hand':
 * https://github.com/adafruit/Adafruit-ST7735-Library/blob/master/Adafruit_ST7735.h
 */

Adafruit_ST7735 tft_ST7735 = Adafruit_ST7735(TFT_CS_ST7735, TFT_DC, TFT_RST_ST7735);
Adafruit_ST7789 tft_ST7789 = Adafruit_ST7789(TFT_CS_ST7789, TFT_DC, TFT_RST_ST7789);

void setup(void) {
  delay(500);
  Serial.begin(115200);
  delay(500);
  Serial.print(F("Hello! ST77xx TFT Test\n"));

  tft_ST7735.initR(INITR_BLACKTAB);      // Init ST7735S chip, green tab
  tft_ST7789.init(240, 320);

  // SPI speed defaults to SPI_DEFAULT_FREQ defined in the library, you can override it here
  // Note that speed allowable depends on chip and quality of wiring, if you go too fast, you
  // may end up with a black screen some times, or all the time.
  //tft.setSPISpeed(40000000);

  Serial.println(F("Initialized"));


  // large block of text
  tft_ST7735.fillScreen(ST77XX_BLACK);
  tft_ST7735.setTextWrap(true);
  tft_ST7735.setTextColor(ST77XX_WHITE);
  tft_ST7789.fillScreen(ST77XX_BLACK);
  tft_ST7789.setTextWrap(true);
  tft_ST7789.setTextColor(ST77XX_WHITE);
  
  tft_ST7735.setCursor(0, 0);
  tft_ST7735.print("Hello ESP32C3");
  tft_ST7789.setCursor(0, 0);
  tft_ST7789.print("Hello ESP32C3");

  tft_ST7735.setCursor(0, 20);
  tft_ST7735.print("Chip Model: " + String(ESP.getChipModel()));
  tft_ST7735.setCursor(0, 30);
  tft_ST7735.print("rotation: " + String(tft_ST7735.getRotation()));
  tft_ST7735.setCursor(0, 40);
  tft_ST7735.print(String(tft_ST7735.width()) + " x " + String(tft_ST7735.height()));

  tft_ST7789.setCursor(0, 20);
  tft_ST7789.print("Chip Model: " + String(ESP.getChipModel()));
  tft_ST7789.setCursor(0, 30);
  tft_ST7789.print("rotation: " + String(tft_ST7789.getRotation()));
  tft_ST7789.setCursor(0, 40);
  tft_ST7789.print(String(tft_ST7789.width()) + " x " + String(tft_ST7789.height()));
  
  delay(2000);

  tft_ST7735.setRotation(3);
  tft_ST7735.setCursor(0, 30);
  tft_ST7735.print("rotation: " + String(tft_ST7735.getRotation()));
  tft_ST7735.setCursor(0, 40);
  tft_ST7735.print(String(tft_ST7735.width()) + " x " + String(tft_ST7735.height()));

  tft_ST7789.setRotation(3);
  tft_ST7789.setCursor(0, 30);
  tft_ST7789.print("rotation: " + String(tft_ST7735.getRotation()));
  tft_ST7789.setCursor(0, 40);
  tft_ST7789.print(String(tft_ST7789.width()) + " x " + String(tft_ST7789.height()));
  
  delay(2000);

  tft_ST7735.fillScreen(ST77XX_RED);
  tft_ST7735.setCursor(50, 50);
  tft_ST7735.print("RED");
  tft_ST7789.fillScreen(ST77XX_RED);
  tft_ST7789.setCursor(50, 50);
  tft_ST7789.print("RED");
  delay(1000);
  tft_ST7735.fillScreen(ST77XX_GREEN);
  tft_ST7735.setCursor(50, 50);
  tft_ST7735.print("GREEN");
  tft_ST7789.fillScreen(ST77XX_GREEN);
  tft_ST7789.setCursor(50, 50);
  tft_ST7789.print("GREEN");
  delay(1000);
  tft_ST7735.fillScreen(ST77XX_BLUE);
  tft_ST7735.setCursor(50, 50);
  tft_ST7735.print("BLUE");
  tft_ST7789.fillScreen(ST77XX_BLUE);
  tft_ST7789.setCursor(50, 50);
  tft_ST7789.print("BLUE");
  delay(1000);

  delay(1000);
  for(int offset=0; offset<tft_ST7735.height()/2; offset++){
    int col;
    if(offset%2 == 0)
      col = ST77XX_WHITE;
    else
      col = ST77XX_BLACK;
      
    tft_ST7735.drawRect(offset, offset, 
                 tft_ST7735.width()-2*offset, tft_ST7735.height()-2*offset,
                 col);
    delay(100);
  }

  int cx_ST7789 = tft_ST7789.width()/2;
  int cy_ST7789 = tft_ST7789.height()/2;
  for(int r=0; r<tft_ST7789.height()/2; r=r+5){

    tft_ST7789.drawCircle(cx_ST7789, cy_ST7789, 
                 r,
                 ST77XX_WHITE);
    delay(100);
  }

  delay(2000);

  Serial.println("- setup() end -");
  delay(1000);
}

void loop() {
  tft_ST7735.invertDisplay(true);
  tft_ST7789.invertDisplay(true);
  delay(500);
  tft_ST7735.invertDisplay(false);
  tft_ST7789.invertDisplay(false);
  delay(500);
}

Next:
~ ESP32-C3/arduino-esp32 + 0.96" 80x160 IPS, create custom class extends Adafruit ST7735 library.

Related:
~ 128x160 TFT/ST7735 SPI wih EP32C3 (arduino-esp32) using Arduino_GFX Library