A20 - Olimex-LCD-10CTS Touch noisy

[mactronica]

Hello.
I had an issue on Olimex-LCD-10CTS + A20 Lime2. Touch was very noisy so i bought a second display and a second Lime2 board. A new cable too. Also the second display worked for some days. Than today the touch become very noisy and if I keep my finger pressed over display the cursor moves crazy. I noticed that if i have the other hand on a ground nearby the touch works well. I built a LVGL demo on Olimex debian bullseye latest image. Even if i use a simple xinit the issue is there.
Can you suggest me how to solve the issue, please?

ThakYou,
Giuseppe.

[mactronica]

I think the sensitivity is too high.

Is there a way to calibrate the sensitivity of goodix GT928 driver?

When i hold the other hand on a ground my body equivalent capacitance should be different, maybe that is why it works. Actually my LCD-10cts displays are not usable. I should modify the driver or implement a digital filter on the touch screen input.

UPDATE: i think my issue is power immunity related. Testing the LCD in the evening/night has no noise problem. During daylight hours the noise reappears. It should be something related to the mains power. So i'm going to test it with a line filter.

[LubOlimex]

How do you power the setup?

[mactronica]

I tested different power sources.
- A raspberryPi official 2,5A 5V power adaptor "stontronics DSA-13PFC-05 FCA"
- A MeanWell HDR-15-5 din rail mount 5V
- HDR-15-5 + Inline Filter GND on metallic frame (setup shown in the video here).

Test showing noise. The cursor move on the same line of pressed point.
https://youtu.be/ut8m9zL3BYs

Test showing that noise disapper holding a finger on the metal frame of the display. Same happens when i hold other hand on a metallic ground near me (ie PC case).


https://youtu.be/ScWoKxNHugE