32F469IDISCOVERY Display Freeze, Touchpanel issue

[Julian_]

Hi all,

we're facing some issues with the STM32F469IDISCOVERY board. Sometimes the display seems to be freezing. I started a debug session yesterday and found out that during this error the ft6x06_TS_GetXY function gets called without touching the display. If the error doesn't occur we can see that the ft6x06_TS_DetectTouch function is called frequently to poll for new touch events, right? Only if there is an event the GetXY function is called to get the proper coodinates for the touch event.

This is why I think that during the error state multiple touch events get rocognized without a real touch event.

Our STM32F469IDISCOVERY board uses the FT6336G touch controller. Is the ft6x06 driver still the newest driver for this controller or is there an alternative (if I create a new TouchGFX project with TouchGFX Designer this driver is also loaded).

Are there any solutions for this behaviour? Thanks.

Julian

[GaetanGodart]

Hello @Julian_ ,

Yes it seems that this is the right driver.

When you create your project in TouchGFX Designer, do you select the correct revision? There was a board revision, so you have to select the correct TBS for your board :

If you want to know if your project freeze, you can add a box and move it one pixel every tick.

Regards,

[Julian_]

Thanks for your answer Gaetan

I used the AU1 version for the newest revision of the board, but we also use the old revision board. The difference is in my opinion only the LCD driver so we can either load the driver for the old LCD or the new LCD. The drivers for the touchpanel ft6x06 should be the same because it is also compatible to FT6336G (I already checked this on the release notes for this driver).

In my opinion this issue coressponds to another root cause. Our programm doesnt freeze so for example temperature values or states are updated corrrectly even if the "freezing display/touch panel error" occures. As I said we get some/lots of touch events during this error state despite we don't touch the display. A real touch event is not recognized correctly because it is "swallowed up" by several ghost touch events. At least that's my assumption at the moment. This is why the display can't be controlled during this error state.

Please note that this error state occures randomly so most of the time there is no issue with the UI.

Do you know if this behaviour is known? Is there a way to get rid of this behaviour if we change settings in the  ft6x06 driver header file? 

Can you onfirm that ft6x06_TS_DetectTouch function is called frequently to poll for new touch events?

If you need some more information please let me know.

Thanks

Julian

[GaetanGodart]

Hello @Julian_ ,

It seems like ft6x06_TS_DetectTouch is called frequently :

/**
  * @brief  Return if there is touches detected or not.
  *         Try to detect new touches and forget the old ones (reset internal global
  *         variables).
  * @param  DeviceAddr: Device address on communication Bus.
  * @retval : Number of active touches detected (can be 0, 1 or 2).
  */

Which version of TouchGFX do you use?

Does the issue happens on multiple board or just one?

Regards,

[Julian_]

Hi Gaetan,

we're using TouchhGFX 4.23.2 Designer. It appears on multiple boards randomly. If you power-cycle device or even if you wait some time (>15min) the error disapears.

Yes that's what I can also confirm from my debug session. The DetectTouch event is polled in an regular interval. But as I alredy wrote the issue is that ft6x06_TS_GetXY gets called without a real TouchEvent.

The UI doesn't get stuck e.g. values get updates but you can't interact with the UI during this error State.

Maybe there were similar problem/issue in the past to get a hint from.

Best,

Julian

[GaetanGodart]

Hello @Julian_ ,

I have not seen similar issue online.
I checked the TBS changes and it doesn't seems like we had this issue previously.
I also never experienced something similar and I am unable to reproduce the issue on my board.

Does the issue happens on an unmodified project?

Can you try to upgrade to TouchGFX 4.2.4.2?

Can you tell me the steps you do to create your project and get to the error so I can try to reproduce it or trouble shot something that you shouldn't be doing?

Regards,

[Julian_]

Hi Gaetan,

let's say we started with a default project out of the Touch GFX Designer, but we modified the project structure a bit. But the TouchGFX Task of RTOS is basiclly the same.

I will investigate this issue further and try it with an example project - I think that I will find a suitable project for this online.

Will come back to you as soon as possible. Thanks

Best,

Julian