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TouchGFX Screen Glitch

sergiog
Associate

I have a custom board which is almost an exact replica of the STM32f769-Disco with the main difference being the processor (STM32F777).

I created a UI with the TouchGFX F769 Disco template and it works flawlessly. It's about 20 screens with about 5 or so widgets per screen. I then created a custom board that replicates the disco board and now I am seeing issues with the screen not updating correctly. During a screen transition the screen glitches or I see artifacts. When I press a button the invalidated area updates but glitches.

My setup is the same as the disco board and my LTDC settings are set to according to the display manufacturers  datasheet (NHD-4.3-800480CF-ASXP-CTP).

What is interesting is that I have a screen with the animated widget that has about 20 pngs and it's the only screen that has no glitches during any screen transition or touch. For some reason, a screen with just a simple background causes no glitches but as soon as add a button or another widget, the screen tears/glitches.

I have tried different timings with the LTDC, double frame buffers, and other parameters to no avail.I have also confirmed that I have enough external RAM and storage.

Main Settings:

Display: Capacitive Touch, 800x480 24bits,

Clock: 200MHz, 40MHz to Display, 100MHz to SRAM,

Single Frame Buffer, DMA2D Enabled, RTOSv2, MPU enabled.

 

The attached video first shows an animated images which when pressed for 2 seconds changes the screen. The screen change glitch appears, then I click a button which causes minor glitching/tearing. I also implemented the keyboard widget and every time I press a key the whole screen glitches/tears.

 

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1 REPLY 1

Hello @sergiog ,

Could you tell us how fast you receive VSync, and how long does it take to render a frame? You can find the instruction for those measurements here .

Thank you 

Mohammad MORADI
ST Software Developer | TouchGFX