low touch refresh rate (TouchGFX)

[SEMad]

Hi.

I am using a custom board (STM32H743IIT6) and GT9271 (it is same as GT911) touch driver... it works properly... but as you see in attached video the touch refresh rate is lower than lcd frame refresh rate (??)...

it is a bit annoying and can cause problem (specially for toggle buttons)...

how can I solve this problem?

thanks.

[Yoann KLEIN]

Hello @SEMad​ ,

Can you provide more details please ?

• Are you using a TouchGFX Board Setup or did you start your project from scratch?
• How do you know that the touch is sampled faster than the display is refreshing? Just by visual inspection?
• What is the frequency of VSYNC? How fast is your board calling OSWrappers::signalVSync() ?
• How are you sampling touch on the display? Polled inside the STMTouchController class? Or through interrupts?

Thanks,

/Yoann

[YShef.1]

Hello, This chip has a lower refresh rate. about 30Hz. (GT911 ~ 100Hz).

1. The first solution is easy -> add code "HAL::setTouchSampleRate(4)".
2. The second way: setup GT9271  to refresh rate 100 Hz. frequency. I'm looking for a solution but haven't found anything yet. If you have any information please let me know.

Thanks,