【STM32N6570-DK】+ LCD绘图和字体显示

1万 · 2025-6-11 23:55

上期通过STM32CubeMX配置LTDC外设实现了lcd屏幕显示，本次继续深入实现lcd绘图和字体显示测试。

由于STM32N6有很大的RAM空间且连续的，这次直接使用LCD整屏RAM buffer显存显示。

LCD整屏显存需要800X480X2=750K。AXISRAM3\4区域各自只有448K，合起来共896K。

具体地址使用AXISRAM3\4区域RAM。由于AXISRAM3\4区域默认是无效的，需要使能时钟和电源。

首先配置一下RAMCFG:

添加额外代码使能代码如下：

  /* SRAM3 and SRAM4 memories clock enable */
  LL_MEM_EnableClock(LL_MEM_AXISRAM3);
  LL_MEM_EnableClock(LL_MEM_AXISRAM4);
  LL_MEM_EnableClock(LL_MEM_AXISRAM4);
  LL_MEM_EnableClock(LL_MEM_AXISRAM4);

  /* Power On AXSRAM3 and AXISRAM4 */
  hramcfg_SRAM3.Instance = RAMCFG_SRAM3_AXI;
  HAL_RAMCFG_EnableAXISRAM(&hramcfg_SRAM3);

  hramcfg_SRAM4.Instance = RAMCFG_SRAM4_AXI;
  HAL_RAMCFG_EnableAXISRAM(&hramcfg_SRAM4);

  hramcfg_SRAM5.Instance = RAMCFG_SRAM5_AXI;
  HAL_RAMCFG_EnableAXISRAM(&hramcfg_SRAM5);

  hramcfg_SRAM6.Instance = RAMCFG_SRAM6_AXI;
  HAL_RAMCFG_EnableAXISRAM(&hramcfg_SRAM6);

设置LCD显存起始地址在

define LCD_LAYER_0_ADDRESS 0x34200000U / SRAM3 /

可以在LTDC初始化中添加显存地址，或者在LTDC初始化之后添加调用如下函数设置显存地址。

HAL_LTDC_SetAddress(&hltdc,(uint32_t )LCD_LAYER_0_ADDRESS,0);

然后打开CACHE和MPU设置，这里要设置显存区域为非CACHE区。否则打开CACHE后显示会不正常。

生成代码之后，添加绘图函数。

/*
 * Copyright (c) 2024, 流水源 Water Source (WoodData).
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date             Author            Notes
 * 2024-06          WoodData          the first version
 */
#include "lcd_buffer.h"


/**
  * [@brief](home.php?mod=space&uid=247401)  Initialize the st7789h2 LCD component.
  * @retval Component status.
  */
uint32_t lcd_buffer_init(void *args)
{

    return 0;
}


uint32_t lcd_buffer_display_on(uint8_t light)
{
    if(light)
    {
        /* Enable backlight */
        //HAL_GPIO_WritePin(LCD_BACKLIGHT_GPIO_PORT, LCD_BACKLIGHT_GPIO_PIN, GPIO_PIN_SET);
    }else
    {
        /* Deactivate backlight */
        //HAL_GPIO_WritePin(LCD_BACKLIGHT_GPIO_PORT, LCD_BACKLIGHT_GPIO_PIN, GPIO_PIN_RESET);
    }
    return 0;
}


uint32_t lcd_buffer_pixel (int16_t x,  int16_t y,  lcd_color_t color)
{
    if((x >= LCD_WIDTH) || (y >= LCD_HEIGHT) || (x<0) || (y<0))    return 1;
    /* Write data value to RAM memory */
    *(__IO uint16_t*) (LCD_LAYER_0_ADDRESS + (2U*((y*LCD_WIDTH) + x))) = (uint16_t)color;
    return 0;
}


uint32_t lcd_buffer_draw_bitmap (uint8_t mode, int16_t x,  int16_t y,  uint16_t w, uint16_t h, const uint8_t *bmp)
{
    uint16_t x0,y0;
    uint16_t *ptr;
    ptr = (uint16_t *) bmp;
    for(y0=0;y0<h;y0++)
    {
        for(x0=0;x0<w;x0++)
        {
            lcd_buffer_pixel(x+x0,y+y0,*ptr++);
        }
    }
    return 0;
}

uint32_t lcd_buffer_fill (int16_t x,  int16_t y,  uint16_t w, uint16_t h, lcd_color_t color)
{
    uint16_t x0,y0;

    for(y0=0;y0<h;y0++)
    {
        for(x0=0;x0<w;x0++)
        {
            lcd_buffer_pixel(x+x0,y+y0,color);
        }
    }
    return 0;
}


uint32_t lcd_buffer_draw_char_dot(uint8_t mode, int16_t x,int16_t y,uint16_t w,uint16_t h,const uint8_t *buff,lcd_color_t f_color,lcd_color_t b_color)
{
    uint32_t i, j;
    uint8_t *ptr= (uint8_t *)buff;

    if((x >= LCD_WIDTH) || (y >= LCD_HEIGHT) || ((x+w)<=0) || ((y+h)<=0))    return 1;
    switch(mode)
    {
        case    0:
            for(i=0;i<h;i++)
            {
                for(j=0;j<w;)
                {
                    if(*ptr & (0x80>>(j&0x07)))
                    {
                        lcd_buffer_pixel(x+j,y+i,f_color);
                    }else
                    {
                        lcd_buffer_pixel(x+j,y+i,b_color);
                    }
                    j++;
                    if(!(j&0x07))
                    {
                        ptr++;
                    }
                }
                if(w & 0x07)    ptr++;
            }

            break;
        case    1:
            for(i=0;i<h;i++)
            {
                for(j=0;j<w;)
                {
                    if(*ptr & (0x01<<(j&0x07)))
                    {
                        lcd_buffer_pixel(x+j,y+i,f_color);
                    }else
                    {
                        lcd_buffer_pixel(x+j,y+i,b_color);
                    }
                    j++;
                    if(!(j&0x07))
                    {
                        ptr++;
                    }
                }
                if(w & 0x07)    ptr++;
            }
            break;
        case    2:
            break;
        case    3:
            break;
    }
    return 0;

}


lcd_adapter_t   lcd_buffer_drv =
{
    .info.sx = 0,
    .info.sy = 0,
    .info.width = LCD_WIDTH,
    .info.height = LCD_HEIGHT,
    .info.color_bit = 16,
    .info.color_type = LCD_RGB565_16BIT,

    .func.init = lcd_buffer_init,
    .func.flush = NULL,
    .func.get_backlight = NULL,
    .func.set_backlight = lcd_buffer_display_on,

    .draw.get_point = NULL,
    .draw.set_point = lcd_buffer_pixel,
    .draw.clear  = NULL,
    .draw.h_line = NULL,
    .draw.v_line = NULL,
    .draw.line = NULL,
    .draw.fill = lcd_buffer_fill,
    .draw.draw_bmp = lcd_buffer_draw_bitmap,
    .draw.draw_char_bmp = lcd_buffer_draw_char_dot, //
};

主函数测试代码如下：

int main(void)
{
  uint32_t i;
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* Enable the CPU Cache */

  /* Enable I-Cache---------------------------------------------------------*/
  SCB_EnableICache();

  /* Enable D-Cache---------------------------------------------------------*/
  SCB_EnableDCache();

  /* MCU Configuration--------------------------------------------------------*/

  /* MPU Configuration--------------------------------------------------------*/
  MPU_Config();
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* Configure the peripherals common clocks */
  PeriphCommonClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_RAMCFG_Init();
  MX_I2C1_Init();
  MX_I2C2_Init();
  MX_LTDC_Init();
  MX_USART1_UART_Init();
  MX_XSPI1_Init();
  SystemIsolation_Config();
  /* USER CODE BEGIN 2 */


  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */

  HAL_LTDC_SetAddress(&hltdc,(uint32_t )LCD_LAYER_0_ADDRESS,0);
  lcd_display_init(&lcd_buffer_drv);

  lcd_clear(LCD_WHITE);
  HAL_Delay(300);
  lcd_clear(LCD_BLACK);
  HAL_Delay(300);
  lcd_clear(LCD_RED);
  HAL_Delay(300);
  lcd_clear(LCD_GREEN);
  HAL_Delay(300);
  lcd_clear(LCD_BLUE);
  HAL_Delay(300);

  for(i=0;i<10;i++){ lcd_draw_line(10+i*50,0,10+i*50,480,LCD_RED);HAL_Delay(200);}
  for(i=0;i<10;i++){lcd_draw_line(0,10+i*40,800,10+i*40,LCD_GREEN);HAL_Delay(200);}
  for(i=0;i<10;i++){lcd_draw_circle(400,240,10+i*20,LCD_YELLOW);HAL_Delay(200);}
  for(i=0;i<10;i++){lcd_draw_rect(400-i*20,240-i*20,i*40,i*40,LCD_MAGENTA);HAL_Delay(200);}

  lcd_fill_rect(80,30,80,80,LCD_RED);
  lcd_draw_image(30,80,80,80,(uint8_t *)c_bmp_muzhu_RGB565);

  lcd_set_font_window(0,0,lcd_get_width(),lcd_get_height());
  lcd_set_font(&Font_ASCII16X8_default);
  lcd_disp_str_at(200,200,"STM32N6-DK");
  lcd_disp_str_at(250,250,"WoodData");

  lcd_set_font(&Font_ASCII24x40);
  lcd_disp_str_at(20,20,"Font_ASCII24x40");
  HAL_Delay(5000);
  while (1)
  {
      lcd_clear(LCD_RED);
      HAL_Delay(1000);
      lcd_clear(LCD_GREEN);
      HAL_Delay(1000);
      lcd_clear(LCD_BLUE);
      HAL_Delay(1000);
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

下面编译烧录查看显示效果：

upload 附件：n6_lcd.zip