the TouchGFX rendering frequency is 60 frames per second； now i want to change the frequency to lower; the main purpose is to save power(most of time i don't need to refresh the LCD)

[Romain DIELEMAN]

Hi,

Maybe this post will help you.

The touchgfx render time is tied closely to the VSYNC of the display. If you wish to lower the fps you can change the pixel clock in your CubeMX project in "Clock Configuration", until you have the desired vsync frequency (16.66ms = 60Hz).

You can measure the vsync/render-time for your concrete application through signals exposed by TouchGFX. Have a look at the implementation of the GPIO class given by Martin in the post I linked.

/Romain

[Mna.1]

Thank you for helping.

You'll excuse me from the side.

This number of 60 (fps) can be calculated by horizontal period * vertical period * LCD_CLK, so

Is it okay to interpret it as being determined by LCD_CLK?

Also, in the case of STM32F769, how many MHz can LCD_CLK be output at the maximum?

Thank you.

[Tliu.2]

Thank you for your helping.

According to what you said, i can change the LCD_CLK to change the fps;

so ,i have a new question:

is the function "handleTickEvent" call frequency equal to fps ?

(the application of graph curve drawing , i hope the frequency of "handleTickEvent" is fixed, even if the fps have being changed)