RT-Thread-LVGL无法正常显示，上电屏幕刷白，运行lcd_test后会出现一部分画面左右颠倒RT-Thread问答社区

LVGL无法正常显示，上电屏幕刷白，运行lcd_test后会出现一部分画面左右颠倒

发布于 2024-12-16 16:40:22 浏览：29 订阅该版

[tocm]

# 主要问题:

* **上电时显示白色**：
  
  * 上电后，LCD 显示器只会显示白色，无法显示 LVGL 的正常画面。
  
  * LVGL 线程正常运行，但未显示预期画面。

* **lcd_test无法显示颜色**：
  
  * 运行lcd_test运行后显示器并未显示红、绿、蓝三种颜色。
  
  * 运行`lcd_test`后LCD显示了 LVGL 画面，但部分画面出现左右颠倒。

# 硬件资源:

- board:STM32H753I-EVAL

- MCU:SMT32H753

- lcd:RGB888 640x480

lcd_port.h:

```c
/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2019-01-08     zylx         first version
 */

#ifndef __LCD_PORT_H__
#define __LCD_PORT_H__

/* 4.3 inch screen, 640 * 480 */
#define LCD_WIDTH           640
#define LCD_HEIGHT          480
#define LV_HOR_RES_MAX    LCD_WIDTH
#define LV_VER_RES_MAX    LCD_HEIGHT
#define LCD_BITS_PER_PIXEL  32
#define LCD_BUF_SIZE        (LCD_WIDTH * LCD_HEIGHT * LCD_BITS_PER_PIXEL / 8) 
#define LCD_PIXEL_FORMAT    RTGRAPHIC_PIXEL_FORMAT_ARGB888

#define LCD_HSYNC_WIDTH     ((uint16_t)30)
#define LCD_VSYNC_HEIGHT    ((uint16_t)3)
#define LCD_HBP             ((uint16_t)114)
#define LCD_VBP             ((uint16_t)32)
#define LCD_HFP             ((uint16_t)16)
#define LCD_VFP             ((uint16_t)10)

#define LCD_BACKLIGHT_USING_GPIO
#define LCD_BL_GPIO_NUM     GET_PIN(A, 6)
#define LCD_DISP_GPIO_NUM   GET_PIN(K, 7)
/* 4.3 inch screen, 640 * 480 */

#endif /* __LCD_PORT_H__ */

```

lv_conf:

```c
/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author        Notes
 * 2021-10-18     Meco Man      First version
 */

#ifndef LV_CONF_H
#define LV_CONF_H

#include <stdint.h>

/*====================
   COLOR SETTINGS
 *====================*/

/*Color depth: 1 (1 byte per pixel), 8 (RGB332), 16 (RGB565), 32 (ARGB8888)*/
#define LV_COLOR_DEPTH 32

#define LV_TICK_CUSTOM 1

/*Enable features to draw on transparent background.
 *It's required if opa, and transform_* style properties are used.
 *Can be also used if the UI is above another layer, e.g. an OSD menu or video player.*/
#define LV_COLOR_SCREEN_TRANSP 0

#define LV_USE_PERF_MONITOR  1

#define LV_CONF_INCLUDE_SIMPLE

/*Use STM32's DMA2D (aka Chrom Art) GPU*/
#define LV_USE_GPU_STM32_DMA2D 1
#if LV_USE_GPU_STM32_DMA2D
    /*Must be defined to include path of CMSIS header of target processor
    e.g. "stm32f7xx.h" or "stm32f4xx.h"*/
    #define LV_GPU_DMA2D_CMSIS_INCLUDE "stm32h7xx.h"
#endif

#endif

```

disp_flush:

```c
static void lcd_fb_flush(lv_disp_drv_t *disp_drv, const lv_area_t *area, lv_color_t *color_p)
{
    uint32_t OffLineSrc = LV_HOR_RES_MAX - (area->x2 - area->x1 + 1);

uint32_t addr = (uint32_t) (SDRAM_BANK_ADDR) + 4 * (LV_HOR_RES_MAX * area->y1 + area->x1);

__HAL_RCC_DMA2D_CLK_ENABLE();

DMA2D->CR &= ~ DMA2D_CR_START;  
    DMA2D->CR = DMA2D_M2M;

DMA2D->FGPFCCR = DMA2D_INPUT_ARGB8888; 
    DMA2D->OPFCCR = DMA2D_OUTPUT_ARGB8888;

/*输入 & 输出寄存器地址*/
    DMA2D->FGMAR = (uint32_t) (uint32_t*) (color_p);

DMA2D->OMAR = (uint32_t) addr; //目标地址
    /*输出窗口（FGOR OOR NLR)*/
    DMA2D->FGOR = 0; //输入偏移量
    DMA2D->OOR = OffLineSrc; //输出偏移量
    DMA2D->NLR = (area->y2 - area->y1 + 1) | ((area->x2 - area->x1 + 1) << 16);
    /*启动DMA2D*/
    DMA2D->CR |= DMA2D_IT_TC | DMA2D_IT_TE | DMA2D_IT_CE; //开启中断
    DMA2D->CR |= DMA2D_CR_START; //启动传输

while (DMA2D->CR & DMA2D_CR_START) {
        // Waiting for transfer to complete
    }

g_gpu_state = RT_TRUE;

lv_disp_flush_ready(disp_drv);
}
```