README.md

ESP32-C3 ( S2, S3, C6, H2? ) and esp32 board package 3.0.3 and ST7789 SPI displays

Cheap Aliexpress displays, tested with a Tasmota Core ESP32-C3 (or an ESP32-C3 Super Mini), Arduino IDE 2.3.2 and TFT_eSPI 2.5.43

Board Package : esp32 3.0.3 ( or esp32 2.0.14 )

Arduino IDE Board : ESP32-C3 Dev Module

Arduino IDE Flash Mode : DIO !!!

All three IPS displays worked stable at 80MHz.

With more changes it also runs on ESP32-C6 and ESP32-H2.

Tasmota Core ESP32-C3

ESP32-S2 or ESP32-S3, TFT_eSPI 2.5.43 and esp32 board package 3.0.3

Add this line to the TFT_eSPI configuration file :

#define USE_HSPI_PORT // HSPI, Pins 10-13

or comment this line for FSPI on ESP32-S2

//#define USE_HSPI_PORT // FSPI, Pins 34-37

For the ESP32-S3 use this line

#define USE_FSPI_PORT // FSPI, Pins 34?-37

ESP32-C3, TFT_eSPI 2.5.43 and esp32 board package 3.0.3 (2.0.14)

There are three options tested :

1. Downgrade the esp32 board package to version 2.0.14 . This is the latest version with no changes required.
2. For ESP32 board package version 3.0.3, two files need to be modified: TFT_eSPI_ESP32_C3.h and the ESP32 package file soc.h for ESP32-C3.
3. The third option requires only changes in TFT_eSPI_ESP32_C3.h

Downgrading is easy, so let's look at the second option, because it shows where the problems are :

Edit the file TFT_eSPI_ESP32_C3.h

C:\Users<username>\Documents\Arduino\libraries\TFT_eSPI\Processors\TFT_eSPI_ESP32_C3.h

and replace line 71

 #define SPI_PORT SPI2_HOST 

with

#if ESP_ARDUINO_VERSION_MAJOR < 3
  #define SPI_PORT SPI2_HOST
#else
  #define SPI_PORT 2
#endif

Edit the second file soc.h

C:\Users<username>\AppData\Local\Arduino15\packages\esp32\tools\esp32-arduino-libs\idf-release_v5.1-bd2b9390ef\esp32c3\include\soc\esp32c3\include\soc\soc.h

Change

#define REG_SPI_BASE(i) (((i)==2) ? (DR_REG_SPI2_BASE) : (0))   // only one GPSPI 

(back) to

#define REG_SPI_BASE(i) (((i)==2) ? (DR_REG_SPI2_BASE) : (DR_REG_SPI0_BASE - ((i) * 0x1000)))

as it was before in version 2.0.14 and exists similar in the soc.h of S2, S3, H2, C3 and C6 but not ESP32.

The third option requires only changes in one file :

Edit the file TFT_eSPI_ESP32_C3.h

C:\Users<username>\Documents\Arduino\libraries\TFT_eSPI\Processors\TFT_eSPI_ESP32_C3.h

and replace line 71

 #define SPI_PORT SPI2_HOST 

with

#if ESP_ARDUINO_VERSION_MAJOR < 3
  #define SPI_PORT SPI2_HOST
#else
  #define SPI_PORT 2
#endif

Then replace

  #ifndef REG_SPI_BASE
    #define REG_SPI_BASE(i) DR_REG_SPI2_BASE
  #endif

with

  #ifdef REG_SPI_BASE
    #undef REG_SPI_BASE
  #endif

  #define REG_SPI_BASE(i) (((i)==2) ? (DR_REG_SPI2_BASE) : (DR_REG_SPI0_BASE - ((i) * 0x1000)))  

That's all. Now the ST7789 display works with my Tasmota ESP32-C3.

Solution for ESP32-C3 found here :

• TFT_eSPI_ESP32_C3.h : Bodmer/TFT_eSPI#3384 (comment)
• soc.h for ESP32-C3 : espressif/arduino-esp32#9618 (comment)

Quote:

The change done in IDF to #define REG_SPI_BASE(i) (((i)>=2) ? (DR_REG_SPI2_BASE + (i-2) * 0x1000) : (0)) // GPSPI2 and GPSPI3
is wrong.  Correct is 
#define REG_SPI_BASE(i) (((i)==2) ? (DR_REG_SPI2_BASE) : (DR_REG_SPI0_BASE - ((i) * 0x1000))) // GPSPI2 and GPSPI3 
Changed this in our IDF fork for Tasmota, which is the base for compiling the Tasmota Arduino libs.
Edit: The changes done for the other SOCs are imho wrong too. Only ESP32 looks correct.

Connections for Tasmota Core ESP32-C3 and ST7789 IPS displays

GPIO	TFT	Description
7	CS	CS
6	SDA	MOSI
5	---	MISO ( not used )
4	SCL	SCLK
19	DC	DC
EN	RST	Reset
18	BLK	3.3V or PWM-Pin
	VCC	3.3V
	GND	GND

Pinout Tasmota Core ESP32-C3

Configuring the TFT_eSPI

Edit or copy the setup file Setup421_C3_ST7789_170x320.h or Setup422_C3_ST7789_240x280.h or Setup423_C3_ST7789_240x320.h :

#define USER_SETUP_ID 421 // 422 // 423

// Driver
#define ST7789_DRIVER   // Configure all registers

#define TFT_WIDTH  170  // 240 // 240 
#define TFT_HEIGHT 320  // 280 // 320

//#define TFT_RGB_ORDER TFT_BGR  // only for display 240x320 
//#define TFT_INVERSION_ON       // only for display 240x320

// Pins ESP32 C3
#define TFT_CS     7
#define TFT_MOSI   6
#define TFT_SCLK   4
#define TFT_MISO   5
#define TFT_DC    19
#define TFT_RST   -1  // Set TFT_RST to -1 if display RESET is connected to ESP32 board EN
//#define TFT_BL  18

// Fonts
#define LOAD_GLCD
#define LOAD_FONT2
#define LOAD_FONT4
#define LOAD_FONT6
#define LOAD_FONT7
#define LOAD_FONT8
//#define LOAD_FONT8N
#define LOAD_GFXFF

#define SMOOTH_FONT

// FSPI / VSPI port (SPI2) used unless following defined. HSPI port is (SPI3) on S3.
//#define USE_HSPI_PORT   // For ESP32 S3 and esp32 board package > 2.0.14

// Other options
//#define SPI_FREQUENCY  27000000  // 80/3 MHz
//#define SPI_FREQUENCY  40000000  // 80/2 MHz
#define SPI_FREQUENCY    80000000  // 80/1 MHz

Edit or copy the file User_Setup_Select.h

Test programs

All files can be found above in the folder Arduino.

• Arduino/ESP32_C3_TFT_graphicstest_170x320.ino
• Arduino/ESP32_C3_TFT_graphicstest_240x280.ino
• Arduino/ESP32_C3_TFT_graphicstest_240x320.ino

ESP32-C3 Super Mini

All files can be found above in the folder ESP32_C3_Super_Mini .

Arduino IDE Board : "Nologo ESP32C3 Super Mini" or "ESP32C3 Dev Module"

ESP32C3 Super Mini

ESP32-C6 (and ESP32-H2)

All files can be found above in the folder ESP32_C6 .

The ESP32-C6 is an upgraded ESP32-C3, so the code of the library TFT_eSPI works here too (but slower).

Four files were modified to verify this :

• TFT_eSPI.h
• TFT_eSPI.cpp
• Processors/TFT_eSPI_ESP32_C3.h
• Processors/TFT_eSPI_ESP32_C3.c

Arduino IDE Board : "ESP32C6 Dev Module"