LVGL学习笔记

芯片启动到LVGL初始化完成大体流程如下:

界面增加打印后代码如下:

static void drag_event_handler(lv_event_t * e)
{
    lv_obj_t * obj = lv_event_get_target(e);

    lv_indev_t * indev = lv_indev_get_act();
    if(indev == NULL)  return;

    lv_point_t vect;
    lv_indev_get_vect(indev, &vect);

    lv_coord_t x = lv_obj_get_x(obj) + vect.x;
    lv_coord_t y = lv_obj_get_y(obj) + vect.y;
    lv_obj_set_pos(obj, x, y);
	LOG_INFO(lvgl_example, "vect x:%d y:%d\r\n",vect.x,vect.y);
}


/**
 * Make an object dragable.
 */
void lv_example_obj_2(void)
{
    lv_obj_t * obj;
    obj = lv_obj_create(lv_scr_act());
    lv_obj_set_size(obj, 150, 100);
    lv_obj_add_event_cb(obj, drag_event_handler, LV_EVENT_PRESSING, NULL);

    lv_obj_t * label = lv_label_create(obj);
    lv_label_set_text(label, "Drag me");
    lv_obj_center(label);

}
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按下复位键到滑动屏幕打印如下:

[INFO] [lcd] lcd_init start
[INFO] [lcd] lcd_init ok
[INFO] [project] BLE Peripheral
[INFO] [project] Local BDADDR: 0x112233445566
[INFO] [project] All service added
[INFO] [project] Start advertising...
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:0 y:0
[INFO] [lvgl_demo] vect x:4 y:2
[INFO] [lvgl_demo] vect x:8 y:11
[INFO] [lvgl_demo] vect x:6 y:5
[INFO] [lvgl_demo] vect x:8 y:5
[INFO] [lvgl_demo] vect x:7 y:4
[INFO] [lvgl_demo] vect x:5 y:3
[INFO] [lvgl_demo] vect x:4 y:2
[INFO] [lvgl_demo] vect x:4 y:1
[INFO] [lvgl_demo] vect x:5 y:1
[INFO] [lvgl_demo] vect x:4 y:1
[INFO] [lvgl_demo] vect x:2 y:0
[INFO] [lvgl_demo] vect x:5 y:-1
[INFO] [lvgl_demo] vect x:1 y:0
[INFO] [lvgl_demo] vect x:0 y:-1
[INFO] [lvgl_demo] vect x:1 y:0
[INFO] [lvgl_demo] vect x:0 y:-1
[INFO] [lvgl_demo] vect x:-1 y:-1
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验证平台事物图:

视频展示效果如下:

配置LOG

使用lv_demo_widgets这个demo:

LOG打印如下:

LV_LOG_WARN("LV_FONT_MONTSERRAT_24 is not enabled for the widgets demo. Using LV_FONT_DEFAULT instead.");

#ifndef LV_LOG_WARN
#  if LV_LOG_LEVEL <= LV_LOG_LEVEL_WARN
#    define LV_LOG_WARN(...) _lv_log_add(LV_LOG_LEVEL_WARN, __FILE__, __LINE__, __func__, __VA_ARGS__)
#  else
#    define LV_LOG_WARN(...) do {}while(0)
#  endif
#endif
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这里打开宏"LV_USE_LOG ",默认的打印级别为:LV_LOG_LEVEL_WARN,这里设置LV_LOG_PRINTF 为1,使用printf输入出:

/*Enable the log module*/
#define LV_USE_LOG 1
#if LV_USE_LOG

    /*How important log should be added:
    *LV_LOG_LEVEL_TRACE       A lot of logs to give detailed information
    *LV_LOG_LEVEL_INFO        Log important events
    *LV_LOG_LEVEL_WARN        Log if something unwanted happened but didn't cause a problem
    *LV_LOG_LEVEL_ERROR       Only critical issue, when the system may fail
    *LV_LOG_LEVEL_USER        Only logs added by the user
    *LV_LOG_LEVEL_NONE        Do not log anything*/
    #define LV_LOG_LEVEL LV_LOG_LEVEL_WARN

    /*1: Print the log with 'printf';
    *0: User need to register a callback with `lv_log_register_print_cb()`*/
    #define LV_LOG_PRINTF 1

    /*Enable/disable LV_LOG_TRACE in modules that produces a huge number of logs*/
    #define LV_LOG_TRACE_MEM        1
    #define LV_LOG_TRACE_TIMER      1
    #define LV_LOG_TRACE_INDEV      1
    #define LV_LOG_TRACE_DISP_REFR  1
    #define LV_LOG_TRACE_EVENT      1
    #define LV_LOG_TRACE_OBJ_CREATE 1
    #define LV_LOG_TRACE_LAYOUT     1
    #define LV_LOG_TRACE_ANIM       1

#endif  /*LV_USE_LOG*/
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_lv_log_add打印函数如下:

void _lv_log_add(lv_log_level_t level, const char * file, int line, const char * func, const char * format, ...)
{
    if(level >= _LV_LOG_LEVEL_NUM) return; /*Invalid level*/

    static uint32_t last_log_time = 0;

    if(level >= LV_LOG_LEVEL) {
        va_list args;
        va_start(args, format);

        /*Use only the file name not the path*/
        size_t p;
        for(p = strlen(file); p > 0; p--) {
            if(file[p] == '/' || file[p] == '\\') {
                p++;    /*Skip the slash*/
                break;
            }
        }

        uint32_t t = lv_tick_get();
        static const char * lvl_prefix[] = {"Trace", "Info", "Warn", "Error", "User"};

#if LV_LOG_PRINTF
        printf("[%s]\t(%" LV_PRId32 ".%03" LV_PRId32 ", +%" LV_PRId32 ")\t %s: ",
               lvl_prefix[level], t / 1000, t % 1000, t - last_log_time, func);
        vprintf(format, args);
        printf(" \t(in %s line #%d)\r\n", &file[p], line);
#else
        if(custom_print_cb) {
            char buf[512];
#if LV_SPRINTF_CUSTOM
            char msg[256];
            lv_vsnprintf(msg, sizeof(msg), format, args);
            lv_snprintf(buf, sizeof(buf), "[%s]\t(%" LV_PRId32 ".%03" LV_PRId32 ", +%" LV_PRId32 ")\t %s: %s \t(in %s line #%d)\n",
                        lvl_prefix[level], t / 1000, t % 1000, t - last_log_time, func, msg, &file[p], line);
#else
            lv_vaformat_t vaf = {format, &args};
            lv_snprintf(buf, sizeof(buf), "[%s]\t(%" LV_PRId32 ".%03" LV_PRId32 ", +%" LV_PRId32 ")\t %s: %pV \t(in %s line #%d)\n",
                        lvl_prefix[level], t / 1000, t % 1000, t - last_log_time, func, (void *)&vaf, &file[p], line);
#endif
            custom_print_cb(buf);
        }
#endif

        last_log_time = t;
        va_end(args);
    }
}
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这里配置printf函数重映射,fputc_imp 应该在库中定义为fputc,这里查不到:

extern int (*fputc_imp)(int ch, FILE *f);

void log_init(void)
{
    fputc_imp = fputc_uart0;
}
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修改代码后工程输出的LOG为:

实验效果请看这个视频:

显示输出

输入设备(TP)

当前LVGL的代码是不关屏的,TP是以定时器去获取的,而追求功耗的案例应该还是靠TP的中断口去获取!