Issue with latest X-CUBE-DISPLAY

[paswenson]

I'm using a NUCLEO-L476RG with a X-NUCLEO-GFX01M1 (MB1642-DT022CTFT-B01). With X-CUBE-DISPLAY v2.0.1, it works fine, but with v2.2.0, after reset, the display just flickers. Any ideas?

[Tesla DeLorean]

Check #defines, or compiler command line options.

Check it's building for the right screen and pins

[paswenson]

This was done using the pre-compiled binaries. They are built for the target Nucleo board and Expansion board.

This works:

\ST\X-CUBE-DISPLAY_v2.0.1\Projects\NUCLEO-L476RG\Applications\GFX01M1_HelloWorld\Binary\GFX01M1_HelloWorld.hex

This does not:

\ST\X-CUBE-DISPLAY-V2_2\Projects\NUCLEO-L476RG\Applications\GFX01M1_HelloWorld\Binary\GFX01M1_HelloWorld.hex

[Tesla DeLorean]

Yes does sound like a problem.

But you'll likely have to rebuild and check what's happening with more specificity and detail, to establish what's actually broken. Probably diff the source to see what changed between versions.

Default pin usages may have changed, support for the M2 display/board also likely added.

Not sure the owner's of the project are active in the forum. If you can establish what the problem is you might get someone to fix or address it.

[Amel NASRI]

Hi @paswenson​,

As suggested by @Community member​, if you can identify the exact issue, this will be very helpful.

Based on your description, there is an issue and I reported it internally.

Internal ticket number: 137684 (This is an internal tracking number and is not accessible or usable by customers).

I'll keep you informed when I get an answer.

-Amel

[Karim BEN BELGACEM · Accepted solution]

Hello,

Yes indeed there is a bug with 2.2.0 when using DMA.

The BSP_[LCD|MEM]_WriteDataDMA was unlocking the APIs at the exit of the API call so transfers could overlaps.

To continue you work until getting the new release which will provide the fix, you can remove call to

MEM_OS_Unlock(Instance); at the end of these functions

lcd_io.c : remove line 462

mem_io.c : remove line 363

Or just disable DMA from the test application and recompile.

app_display.c:

#define USE_MEM_DMA        1

#define USE_LCD_DMA         1

to

#define USE_MEM_DMA        0

#define USE_LCD_DMA         0

Best Regards,

Karim

[paswenson]

Great, thanks for the update.