Great, at least no mystery here.
How do you mean it? What problem has been vanished and how it is flickering? (video please 
)
1 Like
Look at this:
As you can see here, there is not such an effect during the rotation - which we had in the previous video.-
But as I reduced the LCD-TFT clocks from 25 MHz to 12.5 MHz the refresh rate of the LCD is reduced from 48 FPS to 24 FPS. So the display looks flickering -Not sure if this phenomenon is visible in the video-
I can’t really see it in the video but isn’t there a sweet spot between 24 MHz and 48 MHz? E.g. 36MHz?
Probably a memory bus becomes overloaded on the higher frequency. It might be solved by adjusting the memory caching, timing etc but I’m experienced with it enough to give advice remotely.
This issue might be similar:
1 Like
Unfortunately not.
Yeah, I think so.
After a few months, I was able to work on this project again. -this time with my new colleague-
The good news is that the problem of refreshing LCD is solved now 
The solution was solved with the help of Sec 4.5.2 of AN4861 -Optimizing the LTDC framebuffer fetching from external memories-
As this section said, the one line of pixels should be a multiple of 64 for AHB, which was not for me.
The width of LCD is 400, so when I changed it to 384 in the window setting of LTDC and also in lvgl the problem vanished.
Hope this can help some others too.
hello, I want to rotate an image on LCD, but although I wrote in while, the rotation speed is very low. The image goes step by step. What is the solution to these problems?