[联盛德 W803-Pico 试用] TFT 图片显示

本文介绍了联盛德 WM-IoT-SDK 2. X 工程结合 W803-Pico 板实现 TFT 屏幕驱动的项目设计, 包括原理介绍, 代码解析, 效果展示等.

介绍

TFT 彩色液晶屏在日常生活和工作中十分常见且应用广泛, 如便携式显示, 车载显示, 计算机显示 (笔记本电脑, 监视器) , 家电和办公室显示 (电视, 互联网络终端) , 手机, 游戏机, 医疗设备等.

因此了解和学习使用 TFT 显示屏一直是嵌入式开发中的热点话题, 同时驱动 TFT 屏也是考验 MCU 综合性能的极佳指标和参照.

1. 8 寸 TFT 彩屏模块

原理图

管脚定义

参数规格

• 型号: M_TFT_LCD_128X240_8P
• 输入电压: 2. 8V 至 3. 3V
• 供电电流: " 20mA
• 显示类型: 1. 8 inch TFT
• 显示色彩: 262K
• 分辨率: 128 x RGB x 240
• 视角: 12 O'CLOCK
• 驱动 IC: ST7735S
• 接口类型: SPI
• 背光模式: 并联 LED
• 背光驱动方式: PWM
• 结构类型: COG+DIP
• 显示区尺寸: 35x28mm
• 外形尺寸: 55 x 34. 7 x 12 mm
• 工作温度: -20°C ~ 70°C

参考: TFT .

硬件连接

参考: TFT_LCD_DMA — WinnerMicro 在线文档

实物连线

工程测试

介绍了 WM-IoT-SDK 2. X 实现 TFT 屏驱动显示的主要流程.

SDK 框图

这里我们使用 W803-Pico 开发板驱动 TFT 显示屏, 因此 SoC 选择 W803, 组件 - 外设驱动 - TFT LCD - st7735_spi ;

在相应的文件路径下打开例程 wm_iot_sdk/examples/peripheral/tft_lcd/tft_lcd_dma , 右键 menuconfig 配置 SoC (W803) 和 LCD Device (st7735_spi) ;

右键 build 构建工程, 点击 flash 并选择开发板串口对应的端口号, 实现固件上传.

代码

#include  "stdio. h" 
#include "wmsdk_config. h"
#include "freertos/FreeRTOS. h"
#include "freertos/task. h"
#include "freertos/semphr. h"

#include "wm_drv_tft_lcd. h"
#include "wm_drv_sdh_spi. h"
#include "picture. h"
#include "wm_utils. h"

#define LOG_TAG "lcd_example"
#include "wm_log. h"

static void wm_lcd_demo (void *arg) 
{
    int ret = WM_ERR_FAILED; 
    int id  = 0; 

    wm_device_t *dev    = NULL; 
    image_attr_t img    = { 0 }; 
    uint8_t *app_buf    = NULL; 
    uint32_t block_size = 0; 
    uint16_t width = 0,  high = 0; 
    wm_lcd_capabilitys_t cap = { 0 }; 

    lcd_demo_sem = xSemaphoreCreateCounting (1,  1) ; 

    /*TODO:  add more initial methods for other interfaces (like RGB/MIPI. . . )  in future on new chip*/
    /*use sdio (spi mode)  for lcd demo as it's support high speed */
    dev = wm_drv_sdh_spi_init (LCD_SPI_CONTROLLER_DEVICE_NAME) ; 
    if  (dev == NULL)  {
        wm_log_error ("init sdspi fail. ") ; 
    }

    /* initial the lcd device,  and use the same device name which defined in device table*/
    dev = wm_drv_tft_lcd_init (LCD_DEVICE_NAME) ; 
    if  (dev == NULL)  {
        wm_log_info ("init lcd fail. ") ; 
    }

    /* turn on the backlight*/
    ret = wm_drv_tft_lcd_set_backlight (dev,  true) ; 
    if  (ret ! = WM_ERR_SUCCESS)  {
        wm_log_info ("lcd bl set fail. ") ; 
    }

    /* show LCD capability */
    wm_drv_tft_lcd_get_capability (dev,  &cap) ; 
    wm_log_info ("LCD x_resolution = %d",  cap. x_resolution) ; 
    wm_log_info ("LCD y_resolution = %d",  cap. y_resolution) ; 
    wm_log_info ("LCD rotation = %d\n",  cap. rotation) ; 

    //NOTE:  when color mode change ,  the byte width could be adjusted too. 
    /* malloc an application buffer to refresh the screen*/
    width = cap. x_resolution; 
    high  = cap. y_resolution; 

    block_size =  (LCD_DATA_DRAW_LINE_UNIT * width * WM_CFG_TFT_LCD_PIXEL_WIDTH) ; 
    wm_log_info ("DEMO: block_size=%d",  block_size) ; 

    app_buf = malloc (block_size) ; 
    if  (app_buf == NULL)  {
        wm_log_error ("mem err\n") ; 
    }

    /* set image and the image width,  height depend on selected LCD device */
#if CONFIG_COMPONENT_DRIVER_LCD_NV3041A_SPI
    img. image_buf   = image_bluesky_480x272; 
    img. image_width = 480; 
    img. image_high  = 272; 
#else
    img. image_buf   = gImage_pic_winner_micro_logo_93x93; 
    img. image_width = 93; 
    img. image_high  = 93; 
#endif

    if  (img. image_width "  width || img. image_high "  high)  {
        wm_log_error ("image unmatch") ; 
    }

    /* Registers a callback function that gets triggered after the transmission of a bitmap is complete */
    ret = wm_drv_tft_lcd_register_tx_callback (dev,  lcd_demo_tx_cb,  NULL) ; 
    if  (ret ! = WM_ERR_SUCCESS)  {
        wm_log_info ("register tx callback error (%d) ",  ret) ; 
    }

    while  (1)  {
        /* demo scenario 1 - show blue screen by dma*/
        wm_log_info ("wm_lcd_demo show blue background") ; 

        ret = lcd_demo_clean_screen_with_dma (dev,  app_buf,  block_size,  LCD_RGB565_BLUE) ; 
        if  (ret ! = WM_ERR_SUCCESS)  {
            wm_log_info ("wm_lcd_demo_show_image ret=%d",  ret) ; 
        }
        vTaskDelay (pdMS_TO_TICKS (2000) ) ; 

        /* demo scenario 2 - rotation the image once lcd_demo_show_image ()  be invoked*/
        if  (id++ % 2)  {
            ret = wm_drv_tft_lcd_set_rotation (dev,  LCD_ROTATION_NONE) ; 
        } else {
            ret = wm_drv_tft_lcd_set_rotation (dev,  LCD_ROTATION_180_DEGREE) ; 
        }

        /* demo scenario 3 - show image by dma*/
        wm_log_info ("wm_lcd_demo show image (w=%d,  h=%d) ",  img. image_width,  img. image_high) ; 

        ret = lcd_demo_show_image_with_dma (dev,  app_buf,  block_size,  img) ; 
        if  (ret ! = WM_ERR_SUCCESS)  {
            wm_log_info ("wm_lcd_demo_show_image ret=%d",  ret) ; 
        }
        vTaskDelay (pdMS_TO_TICKS (2000) ) ; 
    }

    free (app_buf) ; 

    vSemaphoreDelete ( (QueueHandle_t) lcd_demo_sem) ; 

    vTaskDelete (NULL) ; 
}

int main (void) 
{
    xTaskCreate (wm_lcd_demo,  "wm_lcd_demo_task",  WM_LCD_TFT_DEMO_TASK_STACK,  NULL,  WM_LCD_TFT_DEMO_TASK_PRIO,  NULL) ; 

    return 0; 
}

效果

动态

自定义图片

这里介绍修改工程, 添加并实现自定义图片的 TFT 显示.

图片制作

这里使用 PowerPoint 绘制图文, 另存为 BMP 格式图片;

取模

打开 Image2LCD 软件, 导入目标图片, 配置相关参数 (注意勾选 高位在前 选项) , 输出 . h 格式文件;

调试

将取模文件存放至主函数同一文件夹, 在 picture. h 中增加取模文件 #include "pic_wm. h"

修改 void wm_lcd_demo 函数中关于图片数组的调用信息

img. image_buf   = gImage_wm;  // target picture array name
img. image_width = 93; 
img. image_high  = 93; 

保存文件, 编译工程, 上传固件.

效果

动态

总结

本文介绍了联盛德 WM-IoT-SDK 2. X 工程 Demo 结合 W803-Pico 板实现 TFT 屏幕驱动的项目设计, 包括原理介绍, 硬件连接, 工程测试, 代码调试, 自定义效果展示等, 采用 DMA 硬件 SPI 驱动显示屏, 刷新速度快, 延迟低, 显示质量佳, 为相关驱动开发和显示屏的应用提供了参考.