False touches appears when using multi-touch handler

Question

I am trying to write touch handler driver. Touch driver can give output of 10 simultaneous touches via I2C. I am using Imxrt1176 from NXP.

After writing driver code, I prepared a simple GUI with 10 small rectangles, each representing one finger.

I added multi touch handler widget and write code on: OnPress, OnDrag, OnRelease slots.

When I run my simple GUI tester, I can see every rectangle with my every finger pressed and disappear when I put up my finger. Up to here, everything runs perfectly as I expected. However, I also see some false/wrong rectangles appears randomly & quickly on LCD as if I pressed, a kind of noise. It happens when I press for a long time to the same coordinate, or drag my finger on display, much more it happens not only multi touch, but also even one-finger touch. Why it happens? Is there any filter to prevent it from happening?

Lastly , I am using Emwiz Studio 11. I added time and date picker to my GUI. Even not writing any code, as soon as I generate and run code, code  enters exception, debugger terminates. How can I add date picker? Is there any way? Thanks a lot.

Answer 1

Hello burhanhagi,

the observed behavior indicates problems with touch driver, touch screen or communication with the touch screen. There are two macros in ewconfig.h that can be enabled to check the touch functionality:

EW_PRINT_TOUCH_DATA - This macro prints all touch data reported by the touch driver on the console. This is helpful to test and calibrate the touch device.

EW_PRINT_TOUCH_EVENTS - This macro prints all touch events that are provided to the GUI application. This macro is important for testing during development: Every touch cycle for each finger has to start with one DOWN event followed by 0...n MOVE events and it has to be finalized with one UP event. This sequence is essential and mandatory to provide touch events to the GUI application. When the sequence is incomplete, e.g. you forget to send an UP event, or you mix the finger numbers, the behavior may become unpredictable. 

Try as first to setup a correctly working touch functionality.

Best regards

Paul Banach

Comments

Hello Paul,

I am running my app without problem with version 11. 

I tested my GUI many times. The problem occurred when I add date picker to my GUI app or completely empty project. After compiling & loading compiled files to my own custom board, it crashes. Crashing occurs as soon as app runs. Is it possible to make test(adding time & date picker) to empty project with your imxrt1170 eval board? If my own hardware has instabilities, then how I can run my whole app without problem till adding date picker? When I add datepicker, debugger gives below error:

What I add to my app;

Added both time and date picker

When I try to load compiled .bin file to imxrt1170, as soon as it starts GUI app, just before click on run debug button;

https://ask.embedded-wizard.de/?qa=blob&qa_blobid=10610565866153262306

when I start debug, it gives error

error, GUI not started and stayed lock

 

Here is my custom board and LCD, program stays locked, I could not touch anyhting. Date picker not loaded to GUI as you see. 

program stays locked,datepciker not loaded to GUI, program crashes

As you see, I do nothing except from adding date picker to GUI. Not single line code.

I am using Emwiz 11.00 as per your previous comments. Is it possible to share with me 11.00.01 Embedded wizard Installer?

Thanks a lot

Burhan

 

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Unfortunately I have no HW to make the same test. I will ask my colleagues to help you further.

Best regards

Paul Banach

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Hello Burhan,

as a customer you will find the latest releases of version 11 in the download center using your account. There you will find the 11.00.01 setup.

Concerning the hardfault - this seems not to be related to the touch issue, Correct? In this case please open a separate question, so that we not have a mixture of issues.

Concerning the missing GUI components - I assume there already happens some errors earlier. Can you please share the entire log messages that you receive via serial interface within a console window?

Thanks and best regards,

Manfred.

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Hello Manfred,

thank you for the setup files.

No not touch issue, you are right. I will open another issue if problem continues to exist even using 11.00.01

Actually, no error happens till I click on run debugger. As soon as I click on, it produces that mentioned error. Since I am using my own board, I do not use any console. However, I am running it with debugger line by line.

Program crashes when calling EwUpdate( Viewport, RootObject ) function for the first time running.

Here is the SS of debuger window;

Debugger console window

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Hello Burhan,

within the function EwUpdate() there happens many things - so it is highly recommended to get access to the messages that are reported by the systems. If you do not have a serial connection to your hardware, you can set a breakpoint in EwPrint() and check the reported messages. I assume there are some errors.

Let me know...

Best regards,

Manfred.