xinput_calibration not working anymore on raspbian 9 -> solution

[cabassi]

Hi,

thanks for posting this method, it almost worked for my PenMount 6000 USB.

There's actually an incompatibility with xinput_calibration and the current version of X11.

All the things you do after step 3 are not necessary and won't work.

Please refer to this post for more info: Touchscreen Calibration in Debian9

Also this snippet is very useful to build your transformation matrix: https://codepen.io/GottZ/full/d73f2f844b52b91b7457febce2d1b18c/

If you still read this repo please update your instructions :)

Thank you!