What is my refresh rate (frame per seconds) and can I modify it?

Sure!

You can use a function called

xTaskGetTickCount();

(You might need to include some header file to get access to this) This will give you the current number of ticks. if you compare that number to the number you had last time you went through the loop you should get an idea of how fast you're going.

Similarly:

if(xTaskGetTickCount()-lastSync>syncInterval)
{
	lastSync = xTaskGetTickCount();
	do_something_here...
}

You have to create a variable (of the type long) called 'lastSync' which is the value the xTaskGetTickCount() function returned last.

syncInterval can be a regular int and is used to set the interval between entering the condition.

This snippet is not exactly what you're looking for but rather to time something without using delays.

THIS DOES NOT GUARANTEE CODE EXECUTION WITH A SPECIFIC INTERVAL - rather it allows for the code to check if it is time to perform certain tasks.

If you want code execution at a specific point in time you have to dig a bit deeper in the RTOS code (someone else here might know just where to adjust this)

Addition: Well, it might not guarantee that you execute your code at that EXACT moment, but it will usually be pretty close.

so - to answer your question of how to get the framerate:

1. get the current number of ticks from xTaskGetTickCount()
2. compare the new value to a value saved from the last time you got to this point
3. Divide the clock speed with the difference between the new and old tick value - that is how much time you need to render a frame
4. divide one second by the amount found in 3 and you should have a value for FPS
5. update the value you want to compare with (so when you roll back around you have an updated value to compare against)

I don't have access to cubeIDE right now so might get different results.

Also - you can have a look into some of the demos provided by tGFX. they might have a FPS counter (or was it only MCU load? I can't remember).

Thanks @Community member​ , but could you elaborate please? I open my clock configuration using STM32CubeMX, but I could not find anything like 'pixel clock' and what is total lines?