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Original HOWTO
Documentation License applies to this document Linux Touch
Screen HOWTO
(c) 2002-2006 by Christoph Baumann, cgb(at)debian.org
v3.4 -- Nov 7, 2006 -- the GNU Free
This document describes how to set up a touch screen input device
under XFree86. As the author had only the opportunity to work with
devices from EloTouch(R) and MicroTouch(R) this HOWTO is rather spe-
cific for these devices. The examples given in this HOWTO concentrate
on devices connected via the serial port i.e. /dev/ttyS0 or
/dev/ttyS1. (Information about USB devices would be appreciated!)
______________________________________________________________________
Table of Contents
1. How to configure the device
2. Activating the device
3. Using touch screen and mouse in parallel
4. Configuration under XFree86 4
4.1 Another configuration example
4.2 Addendum
5. Touch Screens on Fujitsu LifeBooks
6. Configuration under X.Org
7. Suggested reading
______________________________________________________________________
1. How to configure the device
Touch screen devices are configured in the Xinput section in the
XF86Config file (mostly /etc/X11/XF86Config or /etc/XF86Config). At
first verify that the device driver modules exist. They are located in
/usr/X11R6/lib/modules/ (the modules for the above mentioned devices
are xf86Elo.so and xf86MuTouch.so). Now have a look into XF86Config.
There should be a section looking like this:
Section "Files"
...
ModulePath "/usr/X11R6/lib/modules"
...
EndSection
To get the module loaded by the X server there has to be a section
like this:
Section "Module"
Load "xf86Elo.so"
EndSection
Now the more tricky part. X needs to know some parameters about the
device. The section for this looks like this (see "man XF86Config"
for more details):
Section "Xinput"
SubSection "Elographics"
#the entry for a MicroTouch device would be SubSection "MicrotouchFinger"
Port "/dev/ttyS1" # for a device at serial port 2
DeviceName "TouchScreen" #could be any unambiguous name
MinimumXPosition 300
MaximumXPosition 3700
MinimumYPosition 300
MaximumYPosition 3700
UntouchDelay 10 #not supported with MuTouch
ReportDelay 10 #not supported with MuTouch
AlwaysCore #activates the device on startup
EndSubSection
EndSection
The values for the entries MinimumXPosition etc. are of course
specific for the setup of the hardware (i.e. depend on the position of
the touch screen relative to the monitor). The values determine where
the points (0,0) and (xmax,ymax) on your monitor (xmax and ymax depend
on the resolution chosen for the Xserver, such as 1024x768) are mapped
on the touch screen. The device driver reads these values and
interpolishes the other coordinates. For illustration:
--------------touch screen area-----------------
I I
I ########visible monitor area############## I
I #x # I
I # (0,0) # I
I # (MinimumXPosition,MinimumYPosition) # I
I # # I
I # # I
I # # I
I # # I
I # # I
I # # I
I # # I
I # (MaximumXPosition,MaximumYPosition)# I
I # (xmax,ymax)# I
I # x# I
I ########################################## I
I I
------------------------------------------------
This mapping can be done by trial and error or by reading the raw
output of the device (needs some serial port programming, see "The
Linux Serial Programming HOWTO"). For the types EloTouch and
MicroTouch exists a rudimentary calibration tool (written by the
author of this document, it can be found at
http://touchcal.sourceforge.net <http://touchcal.sourceforge.net>).
2. Activating the device
After starting X, type in an Xterminal the command
xsetpointer <devicename>
where<devicename> is the name defined in XF86Config with the line
DeviceName ".....", in this example it would be TouchScreen.
To get the device working on startup use the AlwaysCore option in the
touch screen section (see above)
3. Using touch screen and mouse in parallel
To use the touch screen and a mouse in parallel you need to enter the
mouse specs in the Xinput-section. This definitions should be the same
as in the Pointer-section. The following example is for a PS/2-mouse:
Section "Xinput"
SubSection "Mouse"
Protocol "PS/2"
Port "/dev/mouse" #could also be /dev/psaux
DeviceName "Mouse"
AlwaysCore
EndSubSection
...
EndSection
Several people pointed this out, especially the usage of the
AlwaysCore option. Thanks to them all.
4. Configuration under XFree86 4
(from Lee Monamy)
Example XF86Config-4 for an ELO touch screen:
Section "InputDevice"
Identifier "ELO touchscreen"
Driver "elographics"
Option "Device" "/dev/ttyS0"
Option "MinimumXPosition" "300"
Option "MaximumXPosition" "3700"
Option "MinimumYPosition" "300"
Option "MaximumYPosition" "3700"
Option "UntouchDelay" "10"
Option "ReportDelay" "10"
Option "SendCoreEvents" "yes"
EndSection
Noteable differences between this and the version 3 config are that
you specify a Device, *not* a Port, otherwise you get an error. Also,
AlwaysCore from v3 has been replaced with SendCoreEvents.
You must also add to the ServerLayout section, despite that X might
say: "(II) XINPUT: Adding extended input device "TOUCHSCREEN" (type:
Elographics Touch Screen)"
Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen"
InputDevice "Generic Keyboard"
...
InputDevice "ELO touchscreen"
EndSection
4.1. Another configuration example
from Dirk Mueller (for Microtouch SMT3 Series):
Section "InputDevice"
Identifier "MicroTouchFinger"
Driver "mutouch"
Option "Type" "finger"
Option "Device" "/dev/ttyS0"
Option "ScreenNo" "0"
Option "MinimumXPosition" "0"
Option "MaximumXPosition" "16383"
Option "MinimumYPosition" "0"
Option "MaximumYPosition" "16383"
EndSection
Option "Type" can be "finger" or "stylus" Since Microtouch was bought
by 3M-Touch, the resources are on
http://www.3M.com/3MTouchSystems/downloads/legacy.jhtml#Linux
<http://www.3M.com/3MTouchSystems/downloads/legacy.jhtml#Linux>
4.2. Addendum
According to Wong Yeow Sen the configuration option names have changed
in XFree86 4.2 (at least with Red Hat 7.3). If it seems your
calibration values aren't parsed try the following:
...
Option "MinX" "100"
Option "MaxX" "4000"
Option "MinY" "100"
Option "MaxY" "4000"
...
5. Touch Screens on Fujitsu LifeBooks
(from Joerg Hau)
Information about these devices can be found here:
"...
Harald Hoyer's Linux Touch Panel Drivers for the Fujitsu Lifebooks
B112/B142/B2130, http://parzelle.de/Linux/Lifebook/
<http://parzelle.de/Linux/Lifebook/>. Unfortunately, this is XFree 3.x
only and it seems that this information is now "static" (dead?).
Kenan Esau's Lifebook Series B Touchscreen driver, which is the
adaptation of Harald's driver to XFree 4.x.
http://www.conan.de/lifebook/lifebook.html
<http://www.conan.de/lifebook/lifebook.html>.
I [Joerg Hau] have used Kenan's driver on my Fujitsu LifeBook B142
(described at http://www.mysunrise.ch/users/joerg.hau/linux/b142.htm
<http://www.mysunrise.ch/users/joerg.hau/linux/b142.htm>), and it
works like a charm.
..."
6. Configuration under X.Org
(from Kenan Bektas)
Example xorg.conf for an Elo TouchSystems 2216 AccuTouch® USB Touch-
Monitor:
Section "InputDevice"
Identifier "elo"
Driver "elo"
Option "AlwaysCore"
Option "MinX" "300"
Option "MaxX" "3700"
Option "MinY" "300"
Option "MaxY" "3700"
Option "ScreenNumber" "0"
Option "ButtonNumber" "1"
EndSection
7. Suggested reading
· Manpage for XF86Config
· http://www.elotouch.com/Support/linux.asp
<http://www.elotouch.com/support/linux.asp>
· http://www.3M.com/3MTouchSystems/downloads/legacy.jhtml#Linux
<http://www.3M.com/3MTouchSystems/downloads/legacy.jhtml#Linux>
· http://www.hof-berlin.de/tablet/tablet.html <http://www.hof-
berlin.de/tablet/tablet.html> (Thanks to Christer Olofsson for
sending me this URL)
· http://freshmeat.net/projects/xf86elousb
<http://freshmeat.net/projects/xf86elousb> (Driver for iTouch USB)
· The manual shipped with your touch screen :-)
