[Bug]: ST7789V display shows black screen on ESP32-S3 despite correct initialization

[davidmonterocrespo24]

Description

Environment
Board: Waveshare ESP32-S3-Touch-LCD-2.1" (ESP32-S3-WROOM-1-N16R8)
Display: ST7789V 240x320 (via HXR2002C21 controller)
ESP-IDF: v4.4.7
Retro-Go version: 1.46-9-g49b39-dirty

The display backlight turns on and the system boots successfully, but the screen remains completely black (no graphics displayed). The logs show that frames are being rendered (FPS:1, FPS:2) and the display is initialized successfully, but nothing appears on screen.
GPIO Pin Configuration

#define RG_GPIO_LCD_MOSI GPIO_NUM_38
#define RG_GPIO_LCD_CLK GPIO_NUM_39
#define RG_GPIO_LCD_CS GPIO_NUM_45
#define RG_GPIO_LCD_DC GPIO_NUM_42
#define RG_GPIO_LCD_BCKL GPIO_NUM_1
#define RG_GPIO_LCD_RST GPIO_NUM_0
These pins have been verified to be correct through successful testing with ESP-IDF's esp_lcd_panel_st7789 driver.

What Doesn't Work

• Retro-Go launcher shows black screen
• No graphics visible despite successful initialization

Log Output

[info] lcd_set_backlight: backlight set to 80%
[info] rg_display_init: Display ready.
[info] rg_system_init: Retro-Go ready.
[debug] STACK:5312, HEAP:283+7858 (252+7808), BUSY:0%, FPS:2 (S:2 R:0+0), BATT:0

Initialization Sequence Tried
Based on TFT_eSPI library and ST7789 datasheet, I've tried the following initialization sequence:

#define RG_SCREEN_INIT()
ILI9341_CMD(0xB6, 0x0A, 0x82); /* Display Function Control /
ILI9341_CMD(0xB0, 0x00, 0xE0); / RAMCTRL: RAM Control /
ILI9341_CMD(0xB2, 0x0C, 0x0C, 0x00, 0x33, 0x33); / Porch control /
ILI9341_CMD(0xB7, 0x35); / Gate control /
ILI9341_CMD(0xBB, 0x28); / VCOM setting /
ILI9341_CMD(0xC0, 0x0C); / LCM control /
ILI9341_CMD(0xC2, 0x01, 0xFF); / VDV and VRH enable /
ILI9341_CMD(0xC3, 0x10); / VRH set /
ILI9341_CMD(0xC4, 0x20); / VDV set /
ILI9341_CMD(0xC6, 0x0F); / Frame rate 60Hz /
ILI9341_CMD(0xD0, 0xA4, 0xA1); / Power control */

#define RG_SCREEN_WIDTH 240
#define RG_SCREEN_HEIGHT 320
#define RG_SCREEN_ROTATION 0
#define RG_SCREEN_RGB_BGR 0
Also modified ili9341.h to add:
Display Inversion ON (0x21) after Sleep Out (0x11)
CASET (0x2A) and RASET (0x2B) window initialization
120ms delay after Sleep Out

Things I've Tried

• Different MADCTL (0x36) rotation values (0-7)
• RGB vs BGR color mode (RG_SCREEN_RGB_BGR = 0 and 1)
• Display inversion ON (0x21) and OFF (0x20)
• RAMCTRL (0xB0) with parameters from TFT_eSPI (0x00, 0xE0)
• Complete ST7789V power control sequence
• CASET/RASET window initialization
• Different timing delays (10ms, 120ms after Sleep Out)
• Verified all GPIO pins match schematic

Hypothesis
Since the ESP-IDF official driver works but Retro-Go's custom SPI driver doesn't, the issue might be:
Difference in how pixel data is sent via SPI (byte ordering, endianness)
Missing SPI configuration flags
Data format conversion that ESP-IDF handles automatically

Question
Is there any known issue with ST7789V displays and Retro-Go's custom SPI driver? Are there any additional configuration steps needed beyond the standard initialization commands? The fact that frames are being rendered but not displayed suggests the LCD is receiving data but perhaps in the wrong format or the memory window isn't set up correctly for Retro-Go's drawing method.
Additional Information
Working test code using ESP-IDF: Uses esp_lcd_panel_st7789 with esp_lcd_panel_invert_color(panel_handle, true)
SPI configuration: SPI_MODE_0, 40MHz, MSB first
No compilation errors or warnings
Display controller responds to commands (backlight control works, no SPI errors)
Any guidance would be greatly appreciated!

Steps To Reproduce

No response

Environment

• Retro-Go:
• Device:
• OS:
• ESP-IDF:

Anything else?

No response

[DynaMight1124]

Hi

I'm no expert but I have setup a new RetroGo devices. I checked the Waveshare schematics and all looks fine. I assume its this one? https://www.waveshare.com/wiki/ESP32-S3-Touch-LCD-2 (not the round one, which kept popping up)

All the GPIO looks to be fine. Theres a few things I have come across as I had recently used a 240x320 display (portrait), rather than a 320x240 landscape one. I had to set RG_SCREEN_WIDTH and HEIGHT to match what I actually wanted, not what the display was so RG_SCREEN_WIDTH 320 and HEIGHT 240 then use rotation to correct. I cant remember if any of those settings gave a display with backlight but no image, I know some gave a garbled image and basically none worked. So try changing that.

Also there is: #define RG_GPIO_LCD_BCKL_INVERT // Uncomment if the LED is active LOW (Honestly not sure if this can help your issue or not as your backlight seems to be working.)

I would revert any changes made to ili9341.h as well, you can set inversion in the init in config.h if needed

One last thing I actually came across when I was trying to get the CYD working, which was resulting in no image and backlight on, was careful setup of the SPI Host. I needed the SD and Screen to be on different (And certain) hosts and else it wouldnt work. I can see from the schematic they share CLK and MOSI so you may need to play with this.

Hopefully this helps. It looks like quite a cool device too and has a decent amount of additional GPIO, which you dont always see on those types of devices.

Thanks