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Hardware

There are no recommended screens, but the minimum supported resolution is 480x320.

In general, if the device can show a GNU/Linux desktop, then KlipperScreen should work too.

Hardware known to work

Configuration

Follow the manufacturer instructions on how to install your screen. In general if you see a white screen, then it's not properly installed, ensure that you at least see a console, Then install KlipperScreen, if you are having troubles refer to the troubleshooting page for further information.

Screen rotation

Currently there is no support for rotation at runtime, do not use xrandr to rotate the screen. Configure the server to start in the desired orientation, there are many ways to achieve this, here is one:

Create /usr/share/X11/xorg.conf.d/90-monitor.conf

sudo nano /usr/share/X11/xorg.conf.d/90-monitor.conf

Paste this section modifying the options to suit your needs:

Section "Monitor"
    Identifier "DPI-1"
    # This identifier would be the same as the name of the connector printed by xrandr.
    # it can be "HDMI-0" "DisplayPort-0", "DSI-0", "DVI-0", "DPI-0" etc

    Option "Rotate" "left"
    # Valid rotation options are normal,inverted,left,right


    Option "PreferredMode" "1920x1080"
    # May be necesary if you are not getting your prefered resolution.
EndSection
Save the file and restart KlipperScreen.

sudo service KlipperScreen restart

Touchscreen touch rotation

If your touchscreen isn't registering touches properly after the screen has been rotated, you will need to apply a transformation matrix.

First you will need your device name, on a terminal run:

DISPLAY=:0 xinput

Output:

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ ADS7846 Touchscreen                       id=6    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
In this case the device is the ADS7846 Touchscreen, yours may be different

You can test a change by running:

DISPLAY=:0 xinput set-prop "<device name>" 'Coordinate Transformation Matrix' <matrix>

Where the matrix can be one of the following options:

  • 0°: 1 0 0 0 1 0 0 0 1
  • 90° Clockwise: 0 -1 1 1 0 0 0 0 1
  • 90° Counter-Clockwise: 0 1 0 -1 0 1 0 0 1
  • 180° (Inverts X and Y): -1 0 1 0 -1 1 0 0 1
  • invert Y: -1 0 1 1 1 0 0 0 1
  • invert X: -1 0 1 0 1 0 0 0 1

For example:

DISPLAY=:0 xinput set-prop "ADS7846 Touchscreen" 'Coordinate Transformation Matrix' -1 0 1 0 -1 1 0 0 1

To make this permanent, modify the file /etc/udev/rules.d/51-touchscreen.rules and add following line:

ACTION=="add", ATTRS{name}=="<device name>", ENV{LIBINPUT_CALIBRATION_MATRIX}="<matrix>"

As an alternative if the above doesn't work:

edit /usr/share/X11/xorg.conf.d/40-libinput.conf

for example:

Section "InputClass"
        Identifier "libinput touchscreen catchall"
        MatchIsTouchscreen "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "TransformationMatrix" "0 -1 1 1 0 0 0 0 1"
EndSection

More info about input transformation can be found in: