We have been working on configuring a 7-inch Wisecoco touchscreen connected to a Khadas VIM4 running Ubuntu 24.04.1 LTS. Below is a summary of the process and attempts made to achieve optimal touchscreen configuration:
1. Initial Connection and Device Detection
- The touchscreen was connected to the Khadas, and the device was recognized as
wch.cn CH57x, connected at/dev/input/event17. - It was identified that the size reported by
libinputwas incorrect (228x137 mm), while the actual dimensions are 162.7x89.96 mm. This was verified in the manufacturer’s manual. - The device is connected via USB and correctly detects touch but has issues when used through a 3 mm glass.
2. Xorg and Wayland Adjustments
- Initially, we tried to configure the system to use Xorg instead of Wayland for better compatibility.
- In the
/etc/gdm3/custom.conffile, the lineWaylandEnable=falsewas modified to force the use of Xorg, but this caused issues with GDM startup, and the screen did not display. - Eventually, Wayland (
WaylandEnable=true) was restored, as this environment showed better stability for use with the touchscreen.
3. Touchscreen Rotation and Inversion Issues
- It was observed that the touchscreen is operating with incorrect rotation. The screen is mounted in “portrait left” mode, but the touch was inverted: the right side responded to the left and the top to the bottom, as if it were in a “flip”.
- We tried modifying the rotation and calibration parameters in the Xorg configuration file (
/etc/X11/xorg.conf), but the changes had no effect.
4. Touch Calibration
xinput_calibratorwas used to try to calibrate the device, but precise calibration was not achieved.- Additionally, the calibration settings reported by
libinputwere verified, showing an “identity matrix” with no modifications.
5. Persistent Issues
- The touchscreen still does not work properly through the 3 mm glass, despite the manufacturer’s claim that it should operate through 4-8 mm glass.
- The touch detects input but is not correctly aligned with the screen due to incorrect calibration and rotation.
- We attempted to adjust the configuration using
xinputandlibinput, but the lack of an appropriate driver seems to limit the ability to make adjustments.
In summary, we have attempted multiple configurations in Xorg and Wayland, as well as calibration and rotation adjustments, but have not achieved optimal touchscreen functionality through glass on Ubuntu. We request your assistance, pls, to obtain a specific driver or a more suitable configuration for Linux to resolve these issues.Tks in advance!!
OBS: In android and windows 11, all ok!