LTDC Rotation 180 degres

[Hamady]

Hello i'm using touch GFX with STM32H7RS-DK And i need to evaluate for a future product if display rotation is possible.

I tried this implementation but drawCacheEnabled isn't reconize by software so i removed it and the widget is working but the screen flicker betwen 0 and 180° . Is there a more actual way of rotate a screen . 

    // Force redrawing entire screen
    virtual void draw(Rect& rect)
    {
        if (drawCacheEnabled)
        {
            // Invalidate entire screen instead of requested rect.
            Rect r(0, 0, HAL::DISPLAY_WIDTH, HAL::DISPLAY_HEIGHT);
            Application::draw(r);
        }
        else
        {
            // Use original rect if we are *actually* drawing and not just invalidating.
            Application::draw(rect);
        }
    }

 Thanks

[LouisB]

Hello @Hamady,

We do not support 180 rotation, usually for a product, the whole screen itself is rotated. Also some screen support rotation by setting some bits.
It's possible to achieve rotation, by rotating a copy of the framebuffer that you then send to the screen. You can use the GPU to do that with better performances.

May I ask, how did you come up with this code, I dont see how you can have a rotation with just that ?

BR,

[Hamady]

Hello,

Thanks for the quick response 

I got the code from here : https://community.st.com/t5/stm32-mcus-touchgfx-and-gui/repost-change-lcd-orientation-in-180-degree/m-p/376534

Do you have a sampling code or a tuto to achieve this via GPU.

Thanks !

[LouisB]

Hello @Hamady,

This code is from an old version, that is why the "drawCacheEnabled" wasn't working.
I can guide you on how this can be achieved but,I need to know what are the specs for your custom board project (screen resolution, amount of ram, ...) ?

BR,

[Hamady]

Thanks @LouisB 

Screen :https://newhavendisplay.com/3-5-inch-ips-tft-without-touchscreen/

Interface RGB 24bit (No acces to rotation pin and command like GRAM screen i suppose )

Resolution 320x240
Ram 256MB (same as DK board).
Thanks for the help.

[LouisB]

And the chip will be the same as DK board ?

[Hamady]

exactly the same ! 

[Hamady]

Hello,

@LouisB any news about the solution for the GPU2D

Thanks !

[LouisB]

Hello @Hamady,

We are working on a solution internally that uses GPU2D, I will get back to you when I have something.

BR,

[LouisB]

Hello @Hamady,

Here's an example of 180 degrees rotation with GPU2D to summarize we use the NemaGFX to produce a rotated image that is updated, only in the requested areas (it doesn't invalidate the whole screen every frames). I provide a PowerPoint with some additional explanations.

Feel free to ask questions,

BR,