Resolving Touch Screen calibration issues with Ubuntu and the C5518QT Monitor

Does the Dell C5518QT Touch Screen display show touch screen issues with older versions of the Ubuntu Operating System?

Dell C5518QT Touch-screen owners have reported that their displays are not calibrated when performing a default Ubuntu install on an applicable Dell computer.

Those of you using older versions of Ubuntu with the external screen C5518QT may see a gap in the touch functionality. Ubuntu does not calibrate the touch screen by default configuration.

(Figure.1 C5518QT Touchscreen Monitor)

The following steps take you through how to calibrate the C5581QT touch screen monitor. When connected to a Dell computer running 16.04 or older version of the Ubuntu Operating System (OS).

Once the monitor is plugged to the computer, you can calibrate the monitor through a third-party application:

There are several various software utilities available for Ubuntu that help to calibrate the monitor and touch screen capabilities.

xinput_calibrator

The xinput calibrator has been included in Ubuntu since version 12.04. It is available for all the early versions; you can find the full documentation on the following link:

• xinput_calibrator - A generic touch screen calibration program for X.Org 

eGalax Touchscreen

The eGalax Touchscreen has been included in Ubuntu since version 14.04 and you can find all the steps in the following link to the documentation:

• Touchscreen 

Alternatively, once the monitor is plugged to the computer, you can calibrate the monitor through the Xrandr application:

1. Confirm that Xrandr is installed. Typing the following command in Terminal and pressing the Enter key installs the latest version of the application:

   sudo apt-get install xrandr

2. Adjust the video settings:

   1. Start by typing the following command in Terminal and press the Enter key:

      xrandr --output --off

   2. In case you already touched it, reset the Coordinate Transformation Matrix by typing the following command and pressing Enter:

      xinput map-to-output

   3. Calibrate with xinput_calibrator.

   4. Re-enable the screen with the following command in Terminal and press the Enter key:

      xrandr --output –on

3. Edit calibration.conf at the following location:

   • /usr/share/X11/xorg.conf.d/99-calibration.conf:

4. Replace with the following values:

   1. Section "InputClass"

   2. Identifier "calibration"

   3. MatchProduct "ILITEK ILITEK Multi-Touch"

   4. Option "Calibration" "14 10928 15 6122"

   5. Option "SwapAxes" "0"

   6. EndSection

5. Update the line:

   • xinput map-to-output  [touch device] [monitor input]: please you have to identify the monitor device number from LS command and what is the video port used HDMI or DP

     Example: xinput map-to-output 9 HDMI1

6. Close the Terminal window and reboot the computer.

7. Boot back into Ubuntu and open a new Terminal window.

8. Edit .xsessionrc to update the same line xinput map-to-output, as this will keep the touch screen configuration past the next reboot or full shutdown.