Description
What MCU/Processor/Board and compiler are you using?
LVGL 9.1 + ESP32S3 with platformIO (framework : Arduino)
Library use to drive screen : LovyanGFX
Screen used : ILI9488
What LVGL version are you using?
LVGL 9.1
What do you want to achieve?
I want to use 2 full screen size buffer in direct render mode.
What have you tried so far?
Using two partial size buffer with LV_DISPLAY_RENDER_MODE_PARTIAL → Working
Code to reproduce
Partial mode version
Setup () [only revelant part] :
/*Set to your screen resolution*/
#define TFT_HOR_RES 480
#define TFT_VER_RES 320
/*LVGL draw into this buffer, 1/10 screen size usually works well. The size is in bytes*/
#define DRAW_BUF_SIZE ((TFT_HOR_RES * TFT_VER_RES) /10 * (LV_COLOR_DEPTH ) / 4)
uint8_t* draw_buf = (uint8_t *)heap_caps_malloc(DRAW_BUF_SIZE, MALLOC_CAP_SPIRAM);
uint8_t* draw_buf_2 = (uint8_t *)heap_caps_malloc(DRAW_BUF_SIZE, MALLOC_CAP_SPIRAM);
Setup() {
lcd.init();
lcd.setRotation(3);
lv_init();
static lv_display_t *lvDisplay = lv_display_create(TFT_HOR_RES, TFT_VER_RES);
lv_display_set_color_format(lvDisplay, LV_COLOR_FORMAT_RGB565);
lv_display_set_flush_cb(lvDisplay, my_disp_flush);
lv_display_set_buffers(lvDisplay, draw_buf, draw_buf_2, DRAW_BUF_SIZE, LV_DISPLAY_RENDER_MODE_PARTIAL);
}
flush callback :
void my_disp_flush(lv_display_t* display, const lv_area_t* area, unsigned char* data) {
uint32_t w = lv_area_get_width(area);
uint32_t h = lv_area_get_height(area);
lv_draw_sw_rgb565_swap(data, w*h);
if (lcd.getStartCount() == 0) { // Processing if not yet started
lcd.startWrite();
}
lcd.pushImageDMA( area->x1
, area->y1
, area->x2 - area->x1 + 1
, area->y2 - area->y1 + 1
,(uint16_t*) data);
lv_display_flush_ready(display);
}
Direct mode version
I have only changed size of the buffer and buffer configuration :
Setup () *[only revelant part]* :
```c
/*Set to your screen resolution*/
#define TFT_HOR_RES 480
#define TFT_VER_RES 320
/*LVGL draw into this buffer, 1/10 screen size usually works well. The size is in bytes*/
#define DRAW_BUF_SIZE ((TFT_HOR_RES * TFT_VER_RES) * (LV_COLOR_DEPTH ) / 4)
uint8_t* draw_buf = (uint8_t *)heap_caps_malloc(DRAW_BUF_SIZE, MALLOC_CAP_SPIRAM);
uint8_t* draw_buf_2 = (uint8_t *)heap_caps_malloc(DRAW_BUF_SIZE, MALLOC_CAP_SPIRAM);
Setup() {
lcd.init();
lcd.setRotation(3);
lv_init();
static lv_display_t *lvDisplay = lv_display_create(TFT_HOR_RES, TFT_VER_RES);
lv_display_set_color_format(lvDisplay, LV_COLOR_FORMAT_RGB565);
lv_display_set_flush_cb(lvDisplay, my_disp_flush);
lv_display_set_buffers(lvDisplay, draw_buf, draw_buf_2, DRAW_BUF_SIZE, LV_DISPLAY_RENDER_MODE_DIRECT);
}
Screenshot and/or video
Partial mode with “screen scanning” effect : link
Direct mode (not working at all) : link
Post
Hey guys,
As you can see in the video, there is some “screen scanning” effect when loading a new screen (not sure of the translastion in english 
).
To get rid of that I’m trying to work with two full sized buffer. (buffers located in PSRAM)
My code is already working with partial screen buffer but it’s not working at all with two full sized buffers (see the 2nd video).
From reading other post, I understand that I need to edit my ‘flush_cb’ because in DIRECT_MODE, data returned is not the same as in PARTIAL_MODE.
I’m also aware that I need to use DMA because otherwise there is no point in having 2 full sized buffers.
The fact is, I have no idea how to edit my flush callback. I copy-pasted the example from LovyanGFX with a few modification, and it was working (shame on me 
).
My first question is, am I adressing the problem in the right way?
Second question is, how to edit my flush callback ?
Many thanks in advance.
Thomas.
