Problem with semi transparent image on custom hardware

Question

Hi,

Below are 2 images of the same GUI, the left is on the STM32F746Disco, the right is on a custom board using the same flash and the STM32F746 but in a different footprint.

When using the custom hardware, the semi trasparent image appears as rings, not smooth. Any idea what could cause this? We have used this asset with EmWiz 8.3 on our custom hardware without issue.

 

    

Many Thanks

Phil

 

 

Answer 1

Hi Phil,

in general, the different color gradient appearance can have several reasons, e.g.:

• using a reduced color format (e.g. RGB565 instead of RGB888)
• using a different display with lower color resolution (6 bit per color component instead of 8 bit)
• using a different LTDC color format setting
• hardware issues

Maybe you can try to place some color gradients into your application - as it is shown within the example 'ColorFormats' that is provided in all Build Environments.

In case of RGB888 / RGBA8888 it shoul look like this:

In case of RGB565 you will see color steps:

What do yo mean with "We have used this asset with EmWiz 8.3 on our custom hardware without issue."? Are you now using a different version?

Best regards,

Manfred Schweyer.

 

Comments

Hi Manfred,

We will try the 'ColorFormats' and see what happens.

We recently ported across to EmWiz 9.0.

Thanks

Phil