TouchGFX TextArea characters are often shown partially erased on the display

[johnhague]

Hi all

I am currently developing a product that uses a TFT display.  The product uses the following:

STM32F469ZITx
TouchGFX v4.23.2
TFT Module 320 x 240, LTDC RGB565 (16 bits), ST7272
Very often, when displaying text in a TextArea, some of the initial characters look as though they have been erased, as shown below:

The first word should read 'SAFETY'

Sometimes, this reads correctly, eg by cycling through my screens and back to this one.

All of the other items on the screens such as images, buttons, icons etc display with no problems at all.  It's just the TextAreas that are affected. The font used is Verdana, as supplied in TouchGFX.

Any help with this would be most welcome.

[Mohammad MORADI ESFAHANIASL]

Hello @johnhague ,

Are you using the available TouchGFX Board Setup for your project or have you started a completely new project?
Are you storing your TextFlashSection inside external flash or internal one?

Best regards,

[johnhague]

Hi Mohammad

Thanks for replying to my post.

I only joined this project recently, so I have inherited the main code base.  However, it is a custom board, so I would assume that it was started as a completely new project. I will check when the person involved at the very start returns to the office on Monday.

As to your second question, we are only using internal flash at this moment,

Best regards,

John

[Mohammad MORADI ESFAHANIASL]

Okay, I see. Just wanted to make sure that it is a custom board.

Based on the point that you made about the text correctly rendered after cycling through other screen, I would suggest adding a button which on the click invalidates the corrupted TextArea. It is not a solution, it is for testing purpose to observe the behavior of what is happening.

Please try that and update us with your findings.

Kind regards,

[johnhague]

Thanks for the response and idea for testing.

I have just tried that and when the erasing of the text area occurs, pressing my new button (which invalidates the area), does indeed see that area be drawn error-free.

Best regards,

John

[johnhague]

Hi Mohammad

Do you have any thoughts on the results of the tests that I carried out?

Best regards,

John

[JTP1]

Hello John

Can you show how you set for example this 'Safety...' text ? I mean is it wildcard buffer text or use text resources ?

Sometimes it seem to help if the text area is invalidated also before manipulating the text content especially when use some move or resizing- commands.

Br JTP

[johnhague]

Hello JTP

Thanks for the response.

The 'Safety...' text is just a Text Area that has been defined in TouchGFX Designer and is fixed in nature.

Regarding your second comment, I do not manipulate this text whilst running the code.  It is set and displayed in the screen's View Base file, as:

InfoLabelSafetyChecks.setTypedText(touchgfx::TypedText(T_SAFETYCHECKSHEADING));

Best regards,

John

[JTP1]

Hello

I see. Maybe just add some extra invalidate-calls to setupScreen function as a temporary fix (if it works then).

Br JTP

[unsigned_char_array]

Do you use cache? In that case you need to clear the cleaninvalidate the cache.