Waveshare esp32-s3 2.1 touch

[themagicm]

Anyone have an example code that works with this device?

https://www.waveshare.com/esp32-s3-touch-lcd-2.1.htm

[tobozo]

the wiki has a some demo code both for esp-idf and arduino

however there is no existing LGFX config for this device, so you'll have to build your own.

you can use this configuration example as a basis:

• keep Panel_ST7701 section
• replace Touch_GT911 with Touch_CST816S
• edit the pin numbers to match those from the wiki

[themagicm]

So the 816S is compatible with the 820 that is on this display? Sent from Proton Mail Android

…

-------- Original Message --------

On 10/21/24 9:37 AM, tobozo wrote: the [wiki](https://www.waveshare.com/wiki/ESP32-S3-Touch-LCD-2.1) has a some [demo code](https://files.waveshare.com/wiki/ESP32-S3-Touch-LCD-2.1/ESP32-S3-Touch-LCD-2.1-Code.zip) both for esp-idf and arduino however there is no existing config for this device, so you'll have to build your own. you can use [this configuration example](https://github.com/lovyan03/LovyanGFX/blob/master/src/lgfx_user/LGFX_ESP32S3_RGB_MakerfabsParallelTFTwithTouch40.h) as a basis: - keep Panel_ST7701 section - replace Touch_GT911 with [Touch_CST816S](https://github.com/lovyan03/LovyanGFX/blob/master/src/lgfx/v1/touch/Touch_CST816S.cpp) - edit the pin numbers to match those from the wiki — Reply to this email directly, [view it on GitHub](#630 (comment)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/ACW7EAALDGXTAGWHWZB5RY3Z4UGSFAVCNFSM6AAAAABQG6WK3WVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTCMBQGYZTSNI). You are receiving this because you authored the thread.Message ID: ***@***.***>

[tobozo]

yes

https://github.com/lovyan03/LovyanGFX/blob/master/src/lgfx/v1/touch/Touch_CST816S.cpp#L19-L20

[shark526]

hi @themagicm, have you make it work? I'm doing the same but still not work, confusing with EXIO_Init

[fallenartist]

Hi @themagicm I'd also like to know if you've had any success with this display as I'm trying desperately to draw anything on it, so far unsuccessfully. Ta!

[fallenartist]

@tobozo would you be so kind and point me in the right direction? So far I was able to get multicoloured jittering lines on the display ;( I followed the pin declarations from Waveshare example files but, as @shark526 mentioned, there's a "TCA9554PWR I2C GPIO expansion chip (EXIO)" used in demo and I'm not sure how to implement it with LGFX. BTW I reached similar result (sans the jitter) with Arduino GFX, adapting the demo code. Thanks in advance for any pointers.

Pin spec:

• LCD_BL | GPIO6
• LCD_RST | EXIO1
• LCD_SDA | GPIO1
• LCD_SCL | GPIO2
• LCD_CS | EXIO3
• PCLK | GPIO41
• DE | GPIO40
• VSYNC | GPIO39
• HSYNC | GPIO38
• B0 | NC
• B1 | GPIO5
• B2 | GPIO45
• B3 | GPIO48
• B4 | GPIO47
• B5 | GPIO21
• G0 | GPIO14
• G1 | GPIO13
• G2 | GPIO12
• G3 | GPIO11
• G4 | GPIO10
• G5 | GPIO9
• R0 | NC
• R1 | GPIO46
• R2 | GPIO3
• R3 | GPIO8
• R4 | GPIO18
• R5 | GPIO17
• TP_SDA | GPIO15
• TP_SCL | GPIO7
• TP_INT | GPIO16
• TP_RST | EXIO2

My minimal code:

#include <LovyanGFX.hpp>

#include "LGFX_ESP32S3_RGB_WaveshareLCD21.h" // ?

static LGFX lcd;

void setup(void)
{
  lcd.init();
  lcd.setRotation(1);
  lcd.setBrightness(128);
  lcd.setColorDepth(16);

  lcd.fillScreen(0xFF8844u);
}

void loop(void)
{
  // do nothing for now
}

// LGFX_ESP32S3_RGB_WaveshareLCD21.h:

#define LGFX_USE_V1
#include <LovyanGFX.hpp>

#include <lgfx/v1/platforms/esp32s3/Panel_RGB.hpp>
#include <lgfx/v1/platforms/esp32s3/Bus_RGB.hpp>
#include <driver/i2c.h>

class LGFX : public lgfx::LGFX_Device
{
public:

  lgfx::Bus_RGB      _bus_instance;
  lgfx::Panel_ST7701 _panel_instance;
  lgfx::Touch_CST816S  _touch_instance;
  lgfx::Light_PWM   _light_instance;

  LGFX(void)
  {
	{
	  auto cfg = _panel_instance.config();

	  cfg.memory_width  = 480;
	  cfg.memory_height = 480;
	  cfg.panel_width  = 480;
	  cfg.panel_height = 480;

	  cfg.offset_x = 0;
	  cfg.offset_y = 0;

	  _panel_instance.config(cfg);
	}

	{
	  auto cfg = _panel_instance.config_detail();

	  cfg.pin_cs = -1; // EXIO3 ?
	  cfg.pin_sclk = 2;
	  cfg.pin_mosi = 1;

	  _panel_instance.config_detail(cfg);
	}

	{
	  auto cfg = _bus_instance.config();
	  cfg.panel = &_panel_instance;
	  cfg.pin_d0  = GPIO_NUM_5;  // B0
	  cfg.pin_d1  = GPIO_NUM_45;  // B1
	  cfg.pin_d2  = GPIO_NUM_48; // B2
	  cfg.pin_d3  = GPIO_NUM_47; // B3
	  cfg.pin_d4  = GPIO_NUM_21;  // B4
	  cfg.pin_d5  = GPIO_NUM_14;  // G0
	  cfg.pin_d6  = GPIO_NUM_13;  // G1
	  cfg.pin_d7  = GPIO_NUM_12; // G2
	  cfg.pin_d8  = GPIO_NUM_11; // G3
	  cfg.pin_d9  = GPIO_NUM_10; // G4
	  cfg.pin_d10 = GPIO_NUM_9;  // G5
	  cfg.pin_d11 = GPIO_NUM_46; // R0
	  cfg.pin_d12 = GPIO_NUM_3; // R1
	  cfg.pin_d13 = GPIO_NUM_8; // R2
	  cfg.pin_d14 = GPIO_NUM_18; // R3
	  cfg.pin_d15 = GPIO_NUM_17; // R4

	  cfg.pin_henable = GPIO_NUM_40; // DE?
	  cfg.pin_vsync   = GPIO_NUM_39;
	  cfg.pin_hsync   = GPIO_NUM_38;
	  cfg.pin_pclk    = GPIO_NUM_41;
	  cfg.freq_write  = 14000000;

	  cfg.hsync_polarity    = 0;
	  cfg.hsync_front_porch = 50;
	  cfg.hsync_pulse_width = 8;
	  cfg.hsync_back_porch  = 8;
	  cfg.vsync_polarity    = 0;
	  cfg.vsync_front_porch = 8;
	  cfg.vsync_pulse_width = 3;
	  cfg.vsync_back_porch  = 8;
	  cfg.pclk_idle_high    = 0;
	  cfg.de_idle_high      = 1;
	  _bus_instance.config(cfg);
	}
	_panel_instance.setBus(&_bus_instance);

	{
	  auto cfg = _touch_instance.config();
	  cfg.x_min      = 0;
	  cfg.x_max      = 480;
	  cfg.y_min      = 0;
	  cfg.y_max      = 480;
	  cfg.bus_shared = false;
	  cfg.offset_rotation = 0;

	  cfg.i2c_port   = I2C_NUM_1;

	  cfg.pin_int    = GPIO_NUM_NC;
	  cfg.pin_sda    = GPIO_NUM_1;
	  cfg.pin_scl    = GPIO_NUM_2;
	  cfg.pin_rst    = GPIO_NUM_NC; // EXIO1 ?

	  cfg.freq       = 400000;
	  _touch_instance.config(cfg);
	  _panel_instance.setTouch(&_touch_instance);
	}

	{
	  auto cfg = _light_instance.config();
	  cfg.pin_bl = GPIO_NUM_6;
	  _light_instance.config(cfg);
	}
	_panel_instance.light(&_light_instance);

	setPanel(&_panel_instance);
  }
};```

[tobozo]

warning: your code sample includes LovyanGFX twice, make sure both the include and the LGFX config block are placed before setup() and loop(), and only include <LovyanGFX.hpp> once

According to Waveshare zip example, this init sequence handles the backlight, it is called before initializing the LCD:

  I2C_Init();
  TCA9554PWR_Init(0x00);   
  Set_EXIO(EXIO_PIN8,Low);

this is the equivalent of doing this in your setup before tft.init():

  Wire.begin(sda, scl); 
  Wire.beginTransmission(0x20); // I2C device ID
  Wire.write(0x03); // EXIO config reg
  Wire.write(0x00); // EXIO config value
  I2C.endTransmission();
  digitalWrite(EXIO_PIN8, LOW);

jittering: most parallel display issues can be solved by tweaking one of those settings:

	  cfg.hsync_polarity    = 0;
	  cfg.hsync_front_porch = 50;
	  cfg.hsync_pulse_width = 8;
	  cfg.hsync_back_porch  = 8;
	  cfg.vsync_polarity    = 0;
	  cfg.vsync_front_porch = 8;
	  cfg.vsync_pulse_width = 3;
	  cfg.vsync_back_porch  = 8;
	  cfg.pclk_idle_high    = 0;
	  cfg.de_idle_high      = 1;

[fallenartist]

Thanks for a quick reply. Sorry, there are two files joined together in my code block. There's a separate include from // LGFX_ESP32S3_RGB_WaveshareLCD21.h: line.

Can you expand on the EXIO, please? I'm not sure what I should do to actually use it in config for LCD_RST (EXIO1), LCD_CS (EXIO3) and TP_RST (EXIO2, touch?). Do I have to write a function? It's a bit advanced for me I'm afraid.

The backlight is on pin 6, I believe, hence cfg.pin_bl = GPIO_NUM_6;?

Thank you.

[tobozo]

⚠️ cfg_pin_bl is for the backlight signal, not for powering it. ( a GPIO pin couldn't possibly provide that to a LCD panel)

LovyanGFX can drive the backlight signal, but it's up to you to handle whatever power module comes with your board, and have it enabled before using LGFX::init().

Also I don't know this EXIO module at all, my comments were exclusively inspired by what I read in the demo code provided by Waveshare, which I linked earlier.

[fallenartist]

@tobozo sure, I'm just trying to understand it all and need a bit of guidance as I'm way out of my depth here. I hoped for the board to just work and focus on the front-end (designer here). Anyway, from the demo code I gathered the LCD init is as follows:

  I2C_Init(); // Wire.begin(15, 7); 
  TCA9554PWR_Init(0x00); // Wire
  Set_EXIO(EXIO_PIN8, Low); // EXIO8 is buzzer
  ST7701_Reset(); // EXIO1 off and on?
  {
    Set_EXIO(EXIO_PIN1, Low);
    vTaskDelay(pdMS_TO_TICKS(10));
    Set_EXIO(EXIO_PIN1, High);
    vTaskDelay(pdMS_TO_TICKS(50));
  }
  ST7701_Init();
  {
    ST7701_CS_EN(); // EXIO3 off
    {
      Set_EXIO(EXIO_PIN3, Low);
      vTaskDelay(pdMS_TO_TICKS(10));
    }
    // 
    // big init command sequence here
    // 
    ST7701_CS_Dis(); // EXIO3 back on?
    {
      Set_EXIO(EXIO_PIN3, High);
      vTaskDelay(pdMS_TO_TICKS(10));
    }
  } 
  Touch_Init(); // I2C, CST820_ADDR 0x15, CST820_INT_PIN 16
  Backlight_Init(); // ledcAttach(6, 20000, 10); ledcWrite(6, Duty);
}

My question is do you see any potential conflicts with LovyanGFX library?
The screen now got black, with backlight on and touch responding fine.
Is it all just finding the "holy grail" of the exact initialisation sequence or is there more to it?
Thanks again for your help with this.

[tobozo]

potential conflicts may occur with shared bus, but since you've successfully had touch and backlight under simultaneous control I guess it's working fine.

The screen now got black

is that a regression or is it progress? you mentioned jittering earlier, what did it look like?