Image from SD does not load

How-to
1

Description

I am trying to load images from the SD Card, but the “No data” icon appears when rendering

What MCU/Processor/Board and compiler are you using?

STM32F407

What LVGL version are you using?

LVGL: 8.0
lv_fs_if: commit 2cad463d99244822730171243f2646686b4cd14a (on Jun 3, 2021)

What do you want to achieve?

need to draw image from SDCard

What have you tried so far?

I connected FAT FS, checked the file reading by example. Reading works. When I try to read the image, I get “No data”. I convert the image with the parameters:

  • Color format: True Color with Alpha
  • Output format: Binary (tried every)
    When calling a function lv_img_set_src under the debug, you can see that the width and height are determined correctly. I also tried different images in jpg, png formats

Code to reproduce

Example of reading a file (FATFS check)
The code block(s) should be formatted like:

    //Example of reading a file (FATFS check)
    lv_fs_file_t f;
    lv_fs_res_t res;
    res = lv_fs_open(&f, "1:res/test.txt", LV_FS_MODE_RD);

    uint32_t read_num;
    uint8_t buf[8] = {0,};
    res = lv_fs_read(&f, buf, 8, &read_num);
    lv_fs_close(&f);

    //doesn't work like that
    lv_img_set_src(target, "1:res/bleu_img3.bin");
    //this is how it works (C array)
    lv_img_set_src(target, &new_img);

Screenshot and/or video

If possible, add screenshots and/or videos about the current state.

2

Does anyone even have an image output from * .bin read from SD via FATfs? Could you attach your working image and conversion format?

3

Tried using without FATfs. Made on lv_lib_split_jpg Tried to open an example The result is the same “No data” on the object draws with the correct dimensions. Below is an example


    lv_obj_t * img1;
    lv_split_jpeg_init();
    img1 = lv_img_create(parent);
    LV_IMG_DECLARE( wallpaper_sjpg );
    lv_img_set_src( img1,  &wallpaper_sjpg);

Maybe someone came across?
WLfTTpZnqqo

4

what is target here?

5

This happens if you dont have enough RAM and malloc returns nullptr. Using custom malloc that allocates memory on external memory will solve the problem. For me, I set the custom malloc to be heap_caps_malloc (im using esp32 with external psram) and that solves the problem