#include <lvgl.h>
#include <TFT_eSPI.h>
#define screenWidth 320
#define screenHeight 480

TFT_eSPI tft = TFT_eSPI(); /* TFT instance */
static lv_disp_draw_buf_t draw_buf; 

int ledPin = 22; /* 背光PWM */
const int freq = 5000;
const int ledChannel = 0;
const int resolution = 10;

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 );
    int i = 0;

    tft.startWrite();
    tft.setAddrWindow( area->x1, area->y1, w, h );
#if LV_COLOR_DEPTH == 32
    while(i < w* h) {
      int p = *((( uint32_t * )&color_p->full) + i);
      tft_Write_8(p >> 16 & 0xff);
      tft_Write_8(p >> 8 & 0xff);
      tft_Write_8(p & 0xff);
      i++;
    }
#else
    tft.pushColors( ( uint16_t * )&color_p->full, w * h, true );
#endif
    tft.endWrite();
    lv_disp_flush_ready( disp );
}
...
setup()
{
...
  // 背光
  ledcSetup(ledChannel, freq, resolution);
  ledcAttachPin(ledPin, ledChannel);
  ledcWrite(ledChannel, 1023);

  // tft
  tft.begin();
  tft.writecommand(TFT_INVON);
  tft.setRotation(0);
  
  //lvgl
  lv_init();
  /* 放进bss会溢出 */
  void *buf1 = malloc(screenWidth * screenHeight/10 * sizeof(lv_color_t));
  lv_disp_draw_buf_init( &draw_buf, buf1, NULL, screenWidth * screenHeight/10);
  /*Initialize the display*/
  static lv_disp_drv_t disp_drv;
  lv_disp_drv_init( &disp_drv );
  /*Change the following line to your display resolution*/
  disp_drv.hor_res = screenWidth;
  disp_drv.ver_res = screenHeight;
  disp_drv.flush_cb = my_disp_flush;
  disp_drv.draw_buf = &draw_buf;
  lv_disp_drv_register( &disp_drv );
...
}

loop()
{
...
  ledcWrite(ledChannel, bright); // 调整背光
  lv_timer_handler(); 
  delay(5);
}