lvgl是gui层负责绘制gui并根据输入设备的事件来响应重绘 ，然后把绘制的缓冲区发送给显示驱动去实际显示。
以下代码参考lvgl arduino官方例程，gui guider模拟器例程，，零知 stm32 fsmc lvgl例程
第0步 时钟
时钟是lvgl绘制gui的节拍器。获取时钟 在这个文件里 ..\lvgl\src\hal\lv_hal_tick.c
在arduino 中时钟是从 millis（）这个函数获得的
#define LV_TICK_CUSTOM 1
#if LV_TICK_CUSTOM
#define LV_TICK_CUSTOM_INCLUDE "Arduino.h" /*Header for the system time function*/
#define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis()) /*Expression evaluating to current system time in ms*/
#endif /*LV_TICK_CUSTOM*/
stm32使用硬件timer
HardwareTimer *MyTim;
/*Initialize the graphics library's tick*/
MyTim = new HardwareTimer(TIM2);
MyTim->setMode(2, TIMER_OUTPUT_COMPARE); // In our case, channekFalling is configured but not really used. Nevertheless it would be possible to attach a callback to channel compare match.
MyTim->setOverflow(1000/LVGL_TICK_PERIOD, HERTZ_FORMAT); // period in Hz
MyTim->attachInterrupt(lv_tick_handler);
MyTim->resume();
static void lv_tick_handler(HardwareTimer*)
{
lv_tick_inc(LVGL_TICK_PERIOD);
}
linux等使用 mingw标准库 <stddef.h> 里的宏定义 sys_time
#if !LV_TICK_CUSTOM
/**
* You have to call this function periodically
* @param tick_period the call period of this function in milliseconds
*/
LV_ATTRIBUTE_TICK_INC void lv_tick_inc(uint32_t tick_period)
{
tick_irq_flag = 0;
sys_time += tick_period;
}
#endif
第一步 核心初始化
lv核心初始化 完成各种结构体与函数的初始化
lv_init();
第二步 硬件抽象层
硬件虚拟层需要 完成 display, input devices, tick 也就是与驱动的对接，与输入设备的对接 完成tick （节拍）？
1 先看display
先实例化底层显示驱动
SDL驱动 monitor_init();
TFT espi驱动 tft.begin(); /* TFT init TFT初始化*/
tft.setRotation( 1 ); /* Landscape orientation, flipped 设置方向*/
创造缓冲区
/*Create a display buffer SDL样式的*/
static lv_disp_draw_buf_t disp_buf1;
static lv_color_t buf1_1[480 * 10];
lv_disp_draw_buf_init(&disp_buf1, buf1_1, NULL, 480 * 10);
lv_disp_buf_init(&disp_buf, buf, NULL, LV_HOR_RES_MAX * 10);
完成display到实际底层驱动的填充函数
/* Display flushing 显示填充 espi样式 */
void my_disp_flush( lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p )
{
uint32_t w = ( area->x2 - area->x1 + 1 );
uint32_t h = ( area->y2 - area->y1 + 1 );
tft.startWrite();
tft.setAddrWindow( area->x1, area->y1, w, h );
tft.pushColors( ( uint16_t * )&color_p->full, w * h, true );
tft.endWrite();
lv_disp_flush_ready( disp );
}
直接写GRAM样式
void my_disp_flush(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p)
{
u16 height,width;
u16 i,j;
width=area->x2 - area->x1+1; //得到填充的宽度
height=area->y2 - area->y1+1; //高度
for(i=0;i<height;i++)
{
LCD_SetCursor(area->x1,area->y1+i); //设置光标位置
LCD_WriteRAM_Prepare(); //开始写入GRAM
for(j=0;j<width;j++)
{
LCD_TYPE->LCD_RAM=color_p->full;//写入数据
color_p++;
}
}
lv_disp_flush_ready(disp); /* tell lvgl that flushing is done */
}
SDL样式
monitor_flush
创造display
/*Initialize the display初始化display*/
lv_disp_drv_t disp_drv;
lv_disp_drv_init(&disp_drv);
disp_drv.hor_res = LV_HOR_RES_MAX;
disp_drv.ver_res = LV_VER_RES_MAX;
disp_drv.flush_cb = my_disp_flush;// 这里就用到了填充函数
disp_drv.buffer = &disp_buf;
lv_disp_drv_register(&disp_drv);
2 再看输入层
先初始化硬件接口
TFT-esp 这样 触摸屏
uint16_t calData[5] = { 187, 3596, 387, 3256, 5 };
tft.setTouch( calData ); // espi如果设置了touch cs 自动完成触摸的初始化
独立的xpt2046驱动 触摸屏
XPT2046_Touchscreen ts(CS_PIN, irq_pin);
模拟器的鼠标键盘
mouse_init();//在模拟器里也完成了触摸回调函数
其他的滚轮键盘编码器也同样原理
对接触摸驱动 完成触摸回调函数
espi
/*Read the touchpad*/
/*读取触摸板*/
void my_touchpad_read( lv_indev_drv_t * indev_driver, lv_indev_data_t * data )
{
uint16_t touchX, touchY;
bool touched = tft.getTouch( &touchX, &touchY, 600 );
if( !touched )
{
data->state = LV_INDEV_STATE_REL;
}
else
{
data->state = LV_INDEV_STATE_PR;
/*Set the coordinates*/
data->point.x = touchX;
data->point.y = touchY;
Serial.print( "Data x " );
Serial.println( touchX );
Serial.print( "Data y " );
Serial.println( touchY );
}
}
xpt2046
bool my_touchpad_read(lv_indev_drv_t * indev, lv_indev_data_t * data)
{
static lv_coord_t last_x = 0;
static lv_coord_t last_y = 0;
/*Save the state and save the pressed coordinate*/
data->state = ts.touched() ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
if(data->state == LV_INDEV_STATE_PR){
TS_Point p = ts.getPoint();
//convert to lcd position
last_x = LV_HOR_RES-(p.x *LV_HOR_RES)/4095; /*TODO save the current X coordinate*/
last_y = LV_VER_RES-(p.y *LV_VER_RES)/4095; /*TODO save the current Y coordinate*/
Serial.print("touched:");
Serial.print(last_x);Serial.print(",");Serial.println(last_y);
}
/*Set the coordinates (if released use the last pressed coordinates)*/
data->point.x = last_x;
data->point.y = last_y;
return false; /*Return `false` because we are not buffering and no more data to read*/
}
完成lvgl输入驱动与硬件驱动的对接
触摸样式
/*Initialize the (dummy) input device driver*/
/*初始化（虚拟）输入设备驱动程序*/
static lv_indev_drv_t indev_drv;
lv_indev_drv_init( &indev_drv );
indev_drv.type = LV_INDEV_TYPE_POINTER;
indev_drv.read_cb = my_touchpad_read;//上一步的在这用到了
lv_indev_drv_register( &indev_drv );
模拟器样式 使用鼠标
/* Add the mouse as input device
* Use the 'mouse' driver which reads the PC's mouse*/
mouse_init();
lv_indev_drv_t indev_drv;
lv_indev_drv_init(&indev_drv); /*Basic initialization*/
indev_drv.type = LV_INDEV_TYPE_POINTER;
indev_drv.read_cb = mouse_read; /*This function will be called periodically (by the library) to get the mouse position and state*/
lv_indev_t * mouse_indev = lv_indev_drv_register(&indev_drv);
3 初始化节拍
arduino 自动完成此步骤
模拟器
/* Tick init.
* You have to call 'lv_tick_inc()' in periodically to inform LittelvGL about how much time were elapsed
* Create an SDL thread to do this*/
SDL_CreateThread(tick_thread, "tick", NULL);
stm32
/*Initialize the graphics library's tick*/
MyTim = new HardwareTimer(TIM2);
MyTim->setMode(2, TIMER_OUTPUT_COMPARE); // In our case, channekFalling is configured but not really used. Nevertheless it would be possible to attach a callback to channel compare match.
MyTim->setOverflow(1000/LVGL_TICK_PERIOD, HERTZ_FORMAT); // period in Hz
MyTim->attachInterrupt(lv_tick_handler);
MyTim->resume();
说实话我没怎么看懂
第三步 开始绘制gui
硬件抽象层完成初始化 就可以开始绘制ui
从sceen里创建各种widget 给widget添加事件回调 然后在无线循环里调用lv_timer_handler()，它会按LVGL_TICK_PERIOD 设置的事件重复的响应输入事件来重绘ui
这里简单绘制个label
/*Create a Label on the currently active screen在当前屏幕上生成一个label*/
lv_obj_t * label1 = lv_label_create(lv_scr_act(), NULL);// lv_sce_act()可以获得当前屏幕
/*Modify the Label's text设置文本*/
lv_label_set_text(label1, "Hello world!");
lv_obj_set_pos(label1, 0, 230);
/* Align the Label to the center
* NULL means align on parent (which is the screen now)
* 0, 0 at the end means an x, y offset after alignment*/
//
再给他添加一个触摸点击事件 ，让自己的显示文本添加一个感叹号
标签：disp,lv,tick,esp32,drv,stm32,LV,linux,indev From： https://www.cnblogs.com/kyo413/p/16608162.html