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://www.sgoc.de/touchcal.html).
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)
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.
(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
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
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"
...
(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/. 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.
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), and it works like a charm.
..."