pixel error on start up

[realreject]

Current Situation

I have been trying to come up with a fix for pixel error on start up but have been unsuccessful so far.
Any idea what might be causing this? Image below.

Logs

{
  "build": {
    "arduino": {
      "ldscript": "esp32s3_out.ld",
      "memory_type": "qio_opi",
      "partitions": "default_16MB.csv"
    },
    "core": "esp32",
    "extra_flags": [
      "-DESP32S3"
    ],
    "f_cpu": "240000000L",
    "f_flash": "80000000L",
    "flash_mode": "dio",
    "hwids": [
      [
        "0X303A",
        "0x1001"
      ]
    ],
    "mcu": "esp32s3",
    "variant": "esp32s3"
  },
  "connectivity": [
    "wifi",
    "bluetooth"
  ],
  "debug": {
    "openocd_target": "esp32s3.cfg"
  },
  "frameworks": [
    "arduino",
    "espidf"
  ],
  "name": "ESP32-S3 3.5-inch capacitive touch IPS module 8M PSRAM 16M FLASH Arduino LVGL development 320 * 480",
  "upload": {
    "flash_size": "16MB",
    "maximum_ram_size": 327680,
    "maximum_size": 16777216,
    "require_upload_port": true,
    "speed": 921600
  },
  "url": "https://www.aliexpress.com/item/1005007566332450.html?src=google",
  "vendor": "JC3248W535C"
}

Configuration

{
  "build": {
    "arduino": {
      "ldscript": "esp32s3_out.ld",
      "memory_type": "qio_opi",
      "partitions": "default_16MB.csv"
    },
    "core": "esp32",
    "extra_flags": [
      "-DESP32S3"
    ],
    "f_cpu": "240000000L",
    "f_flash": "80000000L",
    "flash_mode": "dio",
    "hwids": [
      [
        "0X303A",
        "0x1001"
      ]
    ],
    "mcu": "esp32s3",
    "variant": "esp32s3"
  },
  "connectivity": [
    "wifi",
    "bluetooth"
  ],
  "debug": {
    "openocd_target": "esp32s3.cfg"
  },
  "frameworks": [
    "arduino",
    "espidf"
  ],
  "name": "ESP32-S3 3.5-inch capacitive touch IPS module 8M PSRAM 16M FLASH Arduino LVGL development 320 * 480",
  "upload": {
    "flash_size": "16MB",
    "maximum_ram_size": 327680,
    "maximum_size": 16777216,
    "require_upload_port": true,
    "speed": 921600
  },
  "url": "https://www.aliexpress.com/item/1005007566332450.html?src=google",
  "vendor": "JC3248W535C"
}

Environment

; PlatformIO Project Configuration File
;
; Build options: build flags, source filter
; Upload options: custom upload port, speed and extra flags
; Library options: dependencies, extra library storages
; Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; https://docs.platformio.org/page/projectconf.html

[platformio]
description = LVGL-320-480
default_envs = LVGL-320-480
boards_dir = boards
data_dir = littlefs
lib_dir = libraries
src_dir = src

[libraries]

[com]
platform = espressif32@6.6.0
board = esp32s3dev
monitor_filters = esp32_exception_decoder
framework = espidf
build_type = debug
board_build.filesystem = littlefs
build_flags =
-D LOG_LOCAL_LEVEL=ESP_LOG_VERBOSE
lib_deps =

[env:LVGL-320-480]
platform = ${com.platform}
board = 320x480
monitor_filters = ${com.monitor_filters}
framework = ${com.framework}
build_type = ${com.build_type}
board_build.filesystem = ${com.board_build.filesystem}
monitor_speed = 115200
lib_deps =
build_flags =
${com.build_flags}
;-D LV_CONF_PATH=${PROJECT_DIR}/src/lv_conf.h
-D LV_CONF_PATH="C:/Users/ryanr/Documents/PlatformIO/Projects/NorthernMan54/JC3248W535EN-main/src/lv_conf.h"

Process Supervisor

hb-service

Additional Context

No response

[NorthernMan54]

Those pixels are likely uninitialized display memory being displayed ie digital noise

[realreject]

I finally fixed it by setting all pixels to black before turning on the back light in the bsp_display_lcd_init() function in esp_bsp.c

static lv_disp_t *bsp_display_lcd_init(const bsp_display_cfg_t *cfg)
{
assert(cfg != NULL);
esp_lcd_panel_io_handle_t io_handle = NULL;

uint32_t hres;
uint32_t vres;

/**
* If the transmission time exceeds the refresh period (time_Tvdl), adopt a 2x period,
* and start data transmission at the falling edge.
*/
hres = EXAMPLE_LCD_QSPI_H_RES;
vres = EXAMPLE_LCD_QSPI_V_RES;
const bsp_display_config_t bsp_disp_cfg = {
    .max_transfer_sz = hres * vres * sizeof(uint16_t),
    .tear_cfg = BSP_SYNC_TASK_CONFIG(EXAMPLE_PIN_NUM_QSPI_TE, GPIO_INTR_NEGEDGE),
};
bsp_display_new(&bsp_disp_cfg, &panel_handle, &io_handle);

/* Add LCD screen */
ESP_LOGD(TAG, "Add LCD screen");
lvgl_port_display_cfg_t disp_cfg = {
    .io_handle = io_handle,
    .panel_handle = panel_handle,
    .buffer_size = cfg->buffer_size,
    .sw_rotate = cfg->rotate,
    .hres = hres,
    .vres = vres,
    .trans_size = hres * vres / 10,
    .draw_wait_cb = bsp_display_sync_cb,
    .flags = {
        .buff_dma = false,
        .buff_spiram = true,
    },
};

if (disp_cfg.sw_rotate == LV_DISP_ROT_180 || disp_cfg.sw_rotate == LV_DISP_ROT_NONE) {
    disp_cfg.hres = hres;
    disp_cfg.vres = vres;
} else {
    disp_cfg.hres = vres;
    disp_cfg.vres = hres;
}

//return lvgl_port_add_disp(&disp_cfg);
//end of original code


// --- Low-Level Black Screen Clear (WARCHILD EDIT)---
// Register the display with LVGL
lv_disp_t *disp = lvgl_port_add_disp(&disp_cfg);



// Clear the physical LCD panel to a black state before the backlight is enabled.
if (panel_handle != NULL) {
    // Allocate a buffer for one horizontal line (DMA-capable memory)
    size_t line_size = hres;
    uint16_t *line_buffer = heap_caps_malloc(line_size * sizeof(uint16_t), MALLOC_CAP_DMA);
    if (line_buffer) {
        // Fill the buffer with black (assume 0x0000 represents black)
        for (size_t i = 0; i < line_size; i++) {
            line_buffer[i] = 0x0000;
        }
        // Write the buffer, one line at a time, across the entire display height
        for (uint32_t y = 0; y < vres; y++) {
            esp_lcd_panel_draw_bitmap(panel_handle, 0, y, hres, y + 1, line_buffer);
        }
        free(line_buffer);
    } else {
        ESP_LOGE(TAG, "Failed to allocate line buffer for clearing the screen");
    }
}

return disp;
// --- End Low-Level Clear ---

}

[NorthernMan54]

Tks for this, do you want to submit a PR ?

[realreject]

I am new at contributing to other project (so not really sure how to do a PR correctly) and currently my project is a long ways from your original repo. Feel free to take and add to your project files Thank you, Ryan

…

On Fri, May 23, 2025, 3:12 a.m. Northern Man ***@***.***> wrote: *NorthernMan54* left a comment (NorthernMan54/JC3248W535EN#10) <#10 (comment)> Tks for this, do you want to submit a PR ? — Reply to this email directly, view it on GitHub <#10 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AVJMFFUEQSFQW7TY6C3SKSD27ZYYXAVCNFSM6AAAAAB5LFS44SVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSMBSHE4TAMJWGY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[DeanK2022]

I had this exact same issue, thanks @realreject !