Rotating TFT Touchscreen (MPI5001)

Hello,

I am using a 5“ TFT Touchscreen (QDtech MPI5001 from Elecrow). It is plugged in via HDMI and also USB for power and touchscreen data.

It works very well and I am quite happy. Almost - since I want to rotate the screen by 180°. This works when adding "display_rotate=2" to config.txt.

The problem is that the touchscreen is not rotated, so I can not use the touch functionality correctly.

There are some scripts at GitHub - goodtft/LCD-show: 2.4" 2.8"3.2" 3.5" 5.0" 7.0" TFT LCD driver for the Raspberry PI 3B+/A/A+/B/B+/PI2/ PI3/ZERO/ZERO W but they do not work with LibreElec.

I did „libinput list-devices“ and this is the output:

Device:           QDtech MPI5001
Kernel:           /dev/input/event0
Group:            1
Seat:             seat0, default
Capabilities:     touch
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    n/a
Middle emulation: n/a
Calibration:      identity matrix
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

How can I edit this device? Is this even possible?

Thanks in advance for your help!

I found out how to do it:

Create a udev rule and store the translation matrix in it:

Create a file like "99-touchscreen.rules" in /storage/.config/udev.rules.d/

Content is

SUBSYSTEM=="input", ATTRS{name}=="QDtech MPI5001", KERNEL=="event*", ENV{LIBINPUT_CALIBRATION_MATRIX}="-1 0 1 0 -1 1"

Took a while, some links:

libinput: Static device configuration via udev

[LE 9.0] Xbox One S Gamepad - no inputs are recognized

To be honest, I really do not have a clue, but take a look at this libinput: Device configuration

Here it is explained how to make your own matrix, so something like "1 0 0 0 1 -0.1" might do the trick. You could use that as a starting point.

Also, you need to find the name of your device, this can be done with "libinput list-devices".

Hope this helps - I am really just stumbling along....