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General Category => Discussion - EVE => Topic started by: Martin on December 01, 2020, 07:46:31 PM

Title: Avoid double touch when screen changes? Finger released detection?
Post by: Martin on December 01, 2020, 07:46:31 PM
Hi,

I have a problem with the operation of a touch display (EVE3-70G)
Assume I have two screens A and B. Each has a number of buttons with individual tags attached. Let's say pressing button X switches to screen B.
As there are different buttons with different tags in screen B, the finger that is still on the position where button X was now triggers a (false) touch on the new screen.
So I need some function like: After switching to a new screen, wait until the finger is lifted before registering new touch events.
How do I best do this?

Thanks - Martin
Title: Re: Avoid double touch when screen changes? Finger released detection?
Post by: BRT Community on December 02, 2020, 10:43:08 AM
Hello,

The touch report rate is determined by the CTP driver IC (ie Focaltech or Goodix). When the CTP interrupt is active, EVE will read and process the touch data. When the CTP is pressed it is possible that the finger is pressed at the same location or moving. In this case it is up to the application to handle the touch events/values/tags.

I would advise checking for the tag to go back to 0 (or whichever clear value was set) to indicate pen-up, or to check the COUTCH_TOUCH_XY register == 0x80008000 for pen-up indication before drawing screen B/reparsing the touch tags in your code.

Best Regards,
BRT Community