LCD Display shake during scrolling Scroll list

[PPanc.1]

Hello,

I've a STM32746G custom board with interface 800x480 resolution LCD.

From Touchgfx I add Scroll list and I've scroll up and down by using hardware key.

Scrolling working fine but whenever I'm scroll up and down then Screen is shake every Scrolling item element Scroll.

From TouchGFX,all Container all text MAXIN use as a Fade Animation and from in Scroll list MAXIN use as a MoveAnimation.

Here I'm share with you code snippet ScreenView.cpp and Container specific file.

So, kindly review and give me a solution, suggestion or any other reference code.

Thanks in advance.

Regards,

Pratik

[Alexandre RENOUX]

Hello,

Are you using an LTDC display ?

I don't think it is due to your UI. But to understand more, try to make a simple screen transition with boxes, or some draggable box that you move around. Also you can try some UI examples available on the Designer and see if you have the same flicker issue. If yes, then it is more about a wrong custom board configuration than the UI in itself. Plus if it is an LTDC display, the TouchGFXHAL should not be the issue.

/Alexandre

[Mada J]

Hi,

I had similar issue. Not only flickering when scrolling ScrolList widget, but it happened also at screen transition and also when I changed Slider value too fast.

Lowering LTDC's frequency has solved these problems. Flickering is now gone.

In my case, I use 7 inch LCD 1024x600 pixel and reconfigure LTDC's frequency from 28Mhz to 22.5Mhz.

Mada

[uilter]

Works for me, thanks for this suggestion.

[mjaan.1]

That cool impact occurs because of the great reaction time (the lower the better) of your screen. The impact is intensified while upward looking over a picture with high difference (extremely splendid + exceptionally dim) level lines that are near one another.

The pixels are going from full splendid to full dim and tight clamp versa in fast movement and the screen needs more chance to stay aware of the looking over speed to keep those pixels changing starting with one outrageous and then onto the next.

Presently the reaction time for a pixel to go from dark to white versus going from white to dark varies too. Pixels rush to go from white to dark and slower to go from dark to white. That is the reason the event that you look cautiously you'd see a path of hazy dark shadow following the picture and disappearing. So assuming the screen has in general low (better) reaction time you wouldn't see any of that. I also face the same issue while working on our company home builder melbourne system.

[uilter]

@mjaan.1​ I always have a doubt about the clock frequency.

In my designs I follow the spesc of typical value, to setup and sync the screen. But its never is true.

We always need to do a "fine tuning".

In your experience, you always did this little adjustments?