Display Configuration Issue with LVGL on STM32H747BIT

[JonConesa]

Hi,

I’m experiencing issues configuring a display using a custom PCB with the STM32H747BIT MCU and LVGL for the UI. Currently, the project runs a minimal setup with only one loop calling lv_timer_handler();. At this point, my main goal is to get the screen working correctly.

I’m using LVGL in direct mode for the display buffers.

The issue I’m facing is that the screen occasionally shows horizontal glitches. I’ve created a simple spinner using the following code:

 /* Create a spinner */
 lv_obj_t * spinner = lv_spinner_create(lv_screen_active());
 lv_obj_set_size(spinner, 64, 64);
 lv_obj_align(spinner, LV_ALIGN_BOTTOM_MID, 0, 0);

You can see the glitch in the attached video.

As you can see, the glitching is more noticeable in Video_1 than in Video_2. These are the display timing configurations used for each:

• Video_1:

• Video_2:

 

Please note that the configuration in Video_1 follows the manufacturer’s recommended settings. In Video_2, I performed some tests and observed that increasing either the front porch or the back porch reduces the glitching. However, those values were set experimentally and not based on any specific guideline.

Is there any display or LVGL configuration step I might be missing that could cause this kind of artifact?

Thanks in advance.

[mƎALLEm]

Hello,

Same here.. For LVGL related questions better to ask your question in LVGL forum: https://forum.lvgl.io/