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Associate
July 16, 2025
Solved

Wildcard text works perfectly in TouchGFX simulator but not when flashed to board!

  • July 16, 2025
  • 3 replies
  • 504 views

I’m working on a TouchGFX project with a dropdown menu. When I select an option, the selected text is shown in a TextArea using a wildcard buffer (selectedTextBuffer).

In the TouchGFX Simulator, the full string displays correctly. But on the actual STM32 board, only the first letter (e.g., just "M") is visible.

I've already tried the following:

  • Set the buffer size in Designer to 32

  • Confirmed that all characters are included in the font's wildcard character set

  • Verified that invalidate() is called after updating text

  • Rebuilt assets and fully flashed the board

Despite all this, the board still only shows the first letter.

Setup:

  • MCU: STM32H7 (STM32H750-DK)

  • TouchGFX version: 4.25.0

  • TextArea uses selectedTextBuffer as wildcard

This topic has been closed for replies.
Best answer by BTKottary27

If you changed the text displayed to something else, "Test", does it always show only the first letter? 

Yes

If you add more M's (keep them capitalized), will it display them?

No, only first letter

Are you using Typed text or creating the text programmatically with snprintf? 

creating using snprintf

If you don't use a wildcard but simply place text in there will it display correctly?

Yes It does.

 

Anyways I used the textID of the buttons in the dropdown menu to set to my desired wildcard text. It worked for me. 

Thanks!

 

3 replies

ST Employee
July 17, 2025

Hello @BTKottary27,

Your text area is big enough to show all the characters ? Try to call resizeToCurrentText() TextArea | TouchGFX Documentation.

BR,

Associate
July 17, 2025

tried resizeToCurrentText() , No changes. It works perfectly fine for me in simulator but not on board!

ST Employee
July 22, 2025

Hello @BTKottary27 

You can try to debug the target, check what value is passed to the textArea and if the invalidation is made correctly.

BR,

jchernus-fikst
Senior
July 23, 2025

Were you able to resolve this?

If you changed the text displayed to something else, "Test", does it always show only the first letter? If you add more M's (keep them capitalized), will it display them? Are you using Typed text or creating the text programmatically with snprintf? If you don't use a wildcard but simply place text in there will it display correctly?

BTKottary27AuthorBest answer
Associate
July 23, 2025

If you changed the text displayed to something else, "Test", does it always show only the first letter? 

Yes

If you add more M's (keep them capitalized), will it display them?

No, only first letter

Are you using Typed text or creating the text programmatically with snprintf? 

creating using snprintf

If you don't use a wildcard but simply place text in there will it display correctly?

Yes It does.

 

Anyways I used the textID of the buttons in the dropdown menu to set to my desired wildcard text. It worked for me. 

Thanks!

 

jchernus-fikst
Senior
July 23, 2025

Great! That's probably the better way to go as it supports localization (different languages, formatting).