Thread: Touchscreen whose drivers play nice with Linux

timekiller:
I have Debian Etch here with a selfcompiled kernel 2.6.18.1 and the debian xorg 7.1.0 precompiled package.
I always try to avoid propetary stuff, so I used the usbtouchscreen kernel module and the evtouch 0.8.0 X-driver.
However, I was too lazy to compile evtouch myself, so I just slapped the precompiled evtouch_drv.o into /usr/lib/xorg/modules/input/ ..it works..

kev000:
So, you are the author of calibrator?
Is it possible to make a regular user-program that gets its input direct from the kernel module and send corrected events as mouse events into the X-system?
If so, it would be nice to have a easy callable user-program that calibrates and corrects for unlinearities in the touch-screen.

It seems to me as the Lilliput touch-screen is a bit crappy, therefore the need for a easy way to recalibrate..

Just my .50 nkr

Originally Posted by noctrl

kev000:
So, you are the author of calibrator?

No, sadly I'm not the author. I found the code on an obscure site and decided to give it a try. It worked well with my touchscreen after I hardcoded my resolution into it.

Touchscreens with Linux seems to be a real show-stopper and something really needs to be done.

Is it possible to make a regular user-program that gets its input direct from the kernel module and send corrected events as mouse events into the X-system?

That might be a solution but I'm currently unable to write such a program in my current knowledge level.

the evtouch driver and the touchscreen does this... almost. It takes the raw data from the input device and sends them to X. I'm currently working on a way to install the driver, run the calibrator for any given resolution, and dynamically change xorg.conf for the new calibration, all automatically. The problem is that while that program will make it easier to setup your touchscreen, it bypasses the underlying problem.

I hear the upcoming versions of xorg will have almost done away with the xorg.conf file and having to restart X. I'm excited to see what that means for us touchscreen users.

kev: thanks for the reply.
I can live with the current status, but its less than ideal of course.
Lets hope someone with the right knowledge steps up and fixes this.
Until then I just make extra BIG buttons for my touchscreen user software

Edit: let me know if you want some help testing the calibrator

Kev and noctrl:

Thanks for the info. I actually never tried the precompiled driver. Tonight I went to download 0.8.0 and saw that the developer updated his driver! The sources for 0.8.1 have a proper configure script, and compiled clean for me. I will have to tinker with it tomorrow to get it calibrated, etc. Very excited about this!!!

FYI: I'm about 90% done with my CarPC reinstall (this time WITH software walkthrough)

Looking forward to pasting it...

kev000!
since you got evtouch working on ubuntu, I was hoping you could post a comment on my setup.
I have compiled kernel 2.6.18.3-custom and it seems to work better than the edgy setup. the touchscreen are responding, and I successfully got the evtouch driver loaded. problem is that when I setup coordinates with the calibration program, the touchscreen becomes accurate, but the mouse can only move on the last y coordinate. who do I get the mouse working at the same time the touchscreen works??

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mouse0"
Option "Protocol" "PS/2"
EndSection

Section "InputDevice"
Identifier "touchscreen0"
Driver "evtouch"
Option "Device" "/dev/input/event2"
Option "DeviceName" "touchscreen"
Option "MinX" "42"
Option "MinY" "988"
Option "MaxX" "965"
Option "MaxY" "70"
#Option "SwapX" "0"
Option "SwapY" "1"
Option "ReportingMode" "Raw"
Option "Emulate3Buttons"
Option "Emulate3Timeout" "50"
Option "SendCoreEvents" "On"
EndSection

from what you posted before I can see that you also got a minY larger than maxY. maximum value should logicaly be larger than a min value

if I do the calibration program, and swap minY and maxY the touchscreen and mouse works perfectly!
I have not added a modproble like you did.
I can see in the calibrator source that it is mentioned that evtouch has y inverted... and still in the sourcecode has the variabel y_inv set to false...

I changed this

Code:

int x_inv = 0, y_inv = 0;

into this

Code:

int x_inv = 0, y_inv = 1;

and now it gives me values that are ready to copy and paste directly

doh. everything works, exept mousedrag with stylus

I changed this
Code:

int x_inv = 0, y_inv = 0;

into this
Code:

int x_inv = 0, y_inv = 1;

and now it gives me values that are ready to copy and paste directly

I'll make inverting x and y an option in the calibrator I'm working on. I'm hoping to make the calibrator automatically edit xorg.conf with the settings to make it a little more automated. This method of automation, however may be problematic as xorg versions change. I guess my question is: Is copy and pasting the values into xorg.conf the best way?

I got to ask, do anyone get touchscreen to do a mouse drag.
and I do not like how evtouch mess the right mouse click button.
I would rather like it to only be left clicks...