从lvgl官网下载到的文件中,主要需要以下选中的文件或文件夹:
在自己的工程中新建文件夹,命名为lvgl,将上述选中文件全部提取至该文件夹中,完整的工程文件树如下:
其中:
porting文件夹中个包含以下文件:
其中:
本随笔中将重点讨论GUI系统的移植,因此此处仅说明disp的模板文件的修改:
#if 0
改为#if 1
使能该文件;/********************** * GLOBAL PROTOTYPES **********************/ void lv_port_disp_init(void);
#if 0
改为#if 1
使能该文件;/** * LVGL requires a buffer where it internally draws the widgets. * Later this buffer will passed to your display driver's `flush_cb` to copy its content to your display. * The buffer has to be greater than 1 display row * * There are 3 buffering configurations: * 1. Create ONE buffer: * LVGL will draw the display's content here and writes it to your display * * 2. Create TWO buffer: * LVGL will draw the display's content to a buffer and writes it your display. * You should use DMA to write the buffer's content to the display. * It will enable LVGL to draw the next part of the screen to the other buffer while * the data is being sent form the first buffer. It makes rendering and flushing parallel. * * 3. Double buffering * Set 2 screens sized buffers and set disp_drv.full_refresh = 1. * This way LVGL will always provide the whole rendered screen in `flush_cb` * and you only need to change the frame buffer's address. */ /* Example for 1) */ #define MY_DISP_HOR_RES 256U static lv_disp_draw_buf_t draw_buf_dsc_1; static lv_color_t buf_1[MY_DISP_HOR_RES * 10]; /*A buffer for 10 rows*/ lv_disp_draw_buf_init(&draw_buf_dsc_1, buf_1, NULL, MY_DISP_HOR_RES * 10); /*Initialize the display buffer*/ // /* Example for 2) */ // static lv_disp_draw_buf_t draw_buf_dsc_2; // static lv_color_t buf_2_1[MY_DISP_HOR_RES * 10]; /*A buffer for 10 rows*/ // static lv_color_t buf_2_2[MY_DISP_HOR_RES * 10]; /*An other buffer for 10 rows*/ // lv_disp_draw_buf_init(&draw_buf_dsc_2, buf_2_1, buf_2_2, MY_DISP_HOR_RES * 10); /*Initialize the display buffer*/ // // /* Example for 3) also set disp_drv.full_refresh = 1 below*/ // static lv_disp_draw_buf_t draw_buf_dsc_3; // static lv_color_t buf_3_1[MY_DISP_HOR_RES * MY_DISP_VER_RES]; /*A screen sized buffer*/ // static lv_color_t buf_3_2[MY_DISP_HOR_RES * MY_DISP_VER_RES]; /*An other screen sized buffer*/ // lv_disp_draw_buf_init(&draw_buf_dsc_3, buf_3_1, buf_3_2, MY_DISP_VER_RES * LV_VER_RES_MAX); /*Initialize the display buffer*/
disp_drv.hor_res = 240; disp_drv.ver_res = 240;
/*Initialize your display and the required peripherals.*/ static void disp_init(void) { st7789_init(); }
/*Flush the content of the internal buffer the specific area on the display *You can use DMA or any hardware acceleration to do this operation in the background but *'lv_disp_flush_ready()' has to be called when finished.*/ static void disp_flush(lv_disp_drv_t * disp_drv, const lv_area_t * area, lv_color_t * color_p) { /*The most simple case (but also the slowest) to put all pixels to the screen one-by-one*/ // int32_t x; // int32_t y; // for(y = area->y1; y <= area->y2; y++) { // for(x = area->x1; x <= area->x2; x++) { // /*Put a pixel to the display. For example:*/ // /*put_px(x, y, *color_p)*/ // st7789_draw_pixel(x, y, color_p->full); // color_p++; // } // } uint16_t x1, y1, x2, y2, size; x1 = area->x1; y1 = area->y1; x2 = area->x2; y2 = area->y2; size = (x2 - x1 + 1) * (y2 - y1 + 1); st7789_set_address(x1, y1, x2, y2); st7789_cfg_dcx_set(); st7789_cfg_spi_write((uint8_t*)color_p, size * 2); /*IMPORTANT!!! *Inform the graphics library that you are ready with the flushing*/ lv_disp_flush_ready(disp_drv); }
lv_conf.h
文件lv_conf_template.h
创建副本并重命名为lv_conf.h
;#if 0
修改为#if 1
以使能该文件;LV_COLOR_16_SWAP
宏定义为1,以解决注册的flush
函数颜色错误问题。听闻LVGL自带非抢占式操作系统,需要时基支持,此处可采用系统自带的滴答定时器中断来实现,如下:
/** * @brief This function handles System tick timer. */ void SysTick_Handler(void) { /* USER CODE BEGIN SysTick_IRQn 0 */ /* USER CODE END SysTick_IRQn 0 */ HAL_IncTick(); /* USER CODE BEGIN SysTick_IRQn 1 */ lv_tick_inc(1); /* USER CODE END SysTick_IRQn 1 */ }
在路径中加入相关的文件路径,如下:
在源文件位置中添加相关文件夹,如下:
首先需经过初始化,如下:
/* USER CODE BEGIN 2 */ lv_init(); lv_port_disp_init(); /* USER CODE END 2 */
其次,非常重要的一步,需要在while (1)
循环中调用lv_task_handler()
函数,如下:
/* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { lv_task_handler(); /* USER CODE END WHILE */ /* USER CODE BEGIN 3 */ } /* USER CODE END 3 */
考虑到函数的使用相对复杂,因此此时库中的例子将有非常重要的参考意义,在使用自带的例子时,只需包含头文件lv_examples.h
即可调用其自带的例子,例如:
/* USER CODE BEGIN 2 */ lv_init(); lv_port_disp_init(); lv_example_keyboard_1(); /* USER CODE END 2 */
最终显示效果如下:
在实际使用中,完成上述移植后,系统的Flash占用率非常高,如下:
为此,应考虑进行合理的剪裁。很遗憾,我尝试过,但并没有成功。