Color order defines take no effect

Question

* Rectangles drawn in EW which are specified as red, display as blue, and vice versa.

* I'm using EW 8.30, and the platform is STM32F4, and the LTDC peripheral is configured for RGB565.

* When I modifiy the values of EW_SCREEN_COLOR_CHANNEL_BIT_OFFSET_RED and EW_SCREEN_COLOR_CHANNEL_BIT_OFFSET_BLUE, they have absolutely no effect.

Does anybody have an idea why the defines to not alter the color order?

Kind Regards,

Rob

Answer 1

Hi Rob,

if you are using the Professional Edition of Embedded Wizard and the STM32 Platform Package, then you have the source code which makes it possible to rebuild the Graphics Engine with the new defines.

If you are using the Libraries (e.g. used within the Free Evaluation Edition) then the color setting is already fixed.

Is there a certain need to change that setting?

Best regards,

Manfred.

Comments

Hi Manfred,

 We are using the professional edition, and I've just rechecked, we were not given source code for:
libewgfx-m4-r90-keil.lib
libewrte-m4-keil.lib

Do you mean the libe files or ewextgfx.c ? We have ewextgfx.c, but that does not make use of the defines. Can ewextgfx.c be modified by us to resolve this?

I've had a look at the LTDC peripheral, and I don't believe the color order can be changed there, which is why the EW defines were so appealing.

Kind Regards,
Rob

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Hi Rob,

according to our records you are using the Small Business Edition, which is provided as libraries - not including the source code.

The file ewextgfx.c is only the lowest layer of the Graphics Engine.

The libraries are prepared for a dedicated hardware scenario (in case of STM32F4 according to DMA2D and LTDC) - so there is typically no need to rebuild that. Does your display / MCU connection has a mismatch between red / blue?

Best regards,

Manfred

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Hi Manfred. Yes, that's correct. Red and Blue are swapped around

Kind Regards,

Rob

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Hi Manfred,

Surely the Small Business Edition should allow those define to take effect?

Kind Regards,

Rob

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Hi Rob,

the Small Business Edition is delivered with libraries, same as the Free Edition just without watermark. Only the Professional Edition is delivered with source codes, so that it is possible to rebuild the entire Graphics Engine with different settings. The color order defines are necessary to configure all software pixel drivers within the Graphics Engine.

Best regards,

Manfred.

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Hi Manfred,

I'm saying that those color order defines do not work,

Kind Regards,

Rob

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Hi Rob,

we will contact you via email to find a solution for you.

Best regards,

Manfred

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Additional technical remark:

There are a couple of configuration flags that can be changed within the makefile in order to change the settings within the Graphics Engine library (e.g. EW_USE_EXTERNAL_FLASH, EW_USE_FREE_RTOS, EW_USE_DOUBLE_BUFFER, ...)

Due to the fact, that defines are evaluated by the compiler, there are many defines within the header files that will not have an effect to an already compiled library.

The defines for the color order are published within the file ewextgfx.h to rebuild the Graphics Engine with different color order (Professional Edition) or to use the current settings within other software parts - e.g. when you make your own implementation of Extern Bitmap, you have to know the color order used within the Graphics Engine.

Best regards,

Manfred.