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Slow fade with touchgfx

sbi
Associate III

I'm using touchgfx 4.22 on a stm32h755zi mcu. The touchgfx run on the M7 core. The mcu is running at 480MHz.
The board is an internal board with a 800x480 display connected in parallel to the LTDC interface with a 18bit bus as shown below:

LTDC.jpg

I use an rgb565 buffer in an external psram. Touchgfx settings are as follow:

Touchgfx conf.jpg

And here the dma2d settings:

DMA2D conf.jpg

I've made a simple screen where there is a fade of a box of 800x480 pixel (all the screen) from gray color to transparent but this fade is very slow. With or without DMA, the result is the same.
Here a video of the fade: https://www.youtube.com/watch?v=OfER5-DQu4M
sorry for the poor video quality; however the screen starts in grey color and after 1 second the box in grey color disappears and another screen is shown. All of this with a fade effect.
And here it is how I made the fade; it's a simple interaction:

Fade.jpg

As far as I understand the fade duration should be 1s but it is 7-8 seconds. A part the wrong duration, the fade is quite sloppy with or without dma.

What am I doing wrong?

14 REPLIES 14

Seems maybe your PLL isnt initialized ok.

sbi
Associate III

This is my clock configuration:

ClockConf1.jpg

ClockConf2.jpg

And this is my RCC settings:

RCC1.jpg

RCC2.jpg

On my board I use this crystal: https://www.ndk.com/images/products/catalog/c_NX2016SA_e.pdf and it is the 25MHz model.
How can I check if the pll is working properly?

sbi
Associate III

I made a little mistake...
TimeWrite is around 170ms
TimeRead is around 100ms
TimeModify is around 188ms

If anyone or @MM..1 has any suggestion... Very appreciate!

Dev80
Associate

I have the exact same problem using the STM32H750.

 

Any solutions in the meantime?

sbi
Associate III

We don't use external ram cause we have a buffer of 384000bytes @ 8bit color depth.

It's quite expensive as ram usage but it works great