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_]

@GaetanGodart 

Hi Gaetan,

hope you are doing fine. I just want to ask you if you know where the Touchpanel RSTN signal (GPIO H7) is set during initialization of the touch panel driver. Signal is set to low in main.c and rises just after initalization- but I can't find out where this happens. --> found it in main.c in MX_DSIHOST_DSI_Init(void)

 

Btw did you already had a look over the video I uploaded?

 

Best,

Julian

[GaetanGodart]

Hello @Julian_ ,

 

I have looked at the video and I reproduced the issue.
But the issue only happens when you increase the size of the swipe container, if you keep it as intended it works fine.
Also, I do not see/experience ghost touch on my project.

 

Regards,

[Julian_]

@GaetanGodart 

Alright, I will check this in the next few days. I don't know why the increasing of the Touch Area (in TouchGFX Designer) should be the cause of this issue.

 

Is there a way to reset the Touch Controller during runtime to handle this error?

 

Thanks and kind regards,

Julian

[GaetanGodart]

Hello @Julian_ ,

 

Ok, no problem.

 

Regards,