Linux Public Driver Touchscreen Installation Instructions 

Linux drivers for Elo touchscreens are available in the public domain, typically on Linux installation CDs and various 
FTP sites such as www.xfree86.org.  These Linux drivers are compatible with Elo AT4 2215, AccuTouch E271-
2210, IntelliTouch E281-2310, IntelliTouch 2500S, and CarrollTouch 4000S serial controllers. The instructions listed 
below are for Red Hat Linux 7.1-7.3 and 8.0. Other versions of Linux including the newest versions may have 
different requirements. Elo TouchSystems is not responsible for the functionality of these drivers and does not support them. 

Driver Installation

1. Install Linux and verify that the X Windows System is working correctly.  We strongly recommend the system be 
configured to start in the command line mode and not be configured to start X Windows automatically.

2. Verify that the Elo touchscreen driver file, elographics_drv.o exists.  Typically, the file can be found at the 
following location: /usr/X11R6/lib/modules/input/elographics_drv.o.

For Redhat Linux 7.1 and 7.2
 
Edit the Configuration File

1. Edit the XF86Config-4 file, normally found in the /etc/X11 directory.  The instructions below are for a touchscreen 
connected to COM one.  In step three below, Option “Device” “/dev/ttyS0” specifies the COM port the touchscreen 
is connected to.  Use Option “Device” “/dev/ttyS0” for COM one, Option “Device” “/dev/ttyS1” for COM two, Option 
“Device” “/dev/ttyS2” for COM three, and Option “Device” “/dev/ttyS3” for COM four.

2. Add the following line to the “ServerLayout” Section:

Inputdevice  “touchscreen1” “SendCoreEvents”

3. Add the following section to the “Inputdevice” section:

Section “Inputdevice” 
              Identifier “touchscreen1” 
              Driver “elographics” 
              Option “Device” “/dev/ttyS0” 
              Option “AlwaysCore” 
              Option “screenno” “0”
              Option “MinimumXPosition” “600” 
              Option “MaximumXPosition” “3600” 
              Option “MinimumYPosition” “600” 
              Option “MaximumYPosition” “3600” 
              Option “UntouchDelay” “3” 
              Option “ReportDelay” “1” 
EndSection

4. Save changes to the XF86Config-4 file.

For Redhat Linux 7.3
 
Edit the Configuration File

1. Edit the XF86Config-4 file, normally found in the /etc/X11 directory.  The instructions below are for a touchscreen 
connected to COM one.  In step three below, Option “Device” “/dev/ttyS0” specifies the COM port the touchscreen 
is connected to.  Use Option “Device” “/dev/ttyS0” for COM one, Option “Device” “/dev/ttyS1” for COM two, Option 
“Device” “/dev/ttyS2” for COM three, and Option “Device” “/dev/ttyS3” for COM four.

2. Add the following line to the “ServerLayout” Section:

Inputdevice  “touchscreen1” “SendCoreEvents”

3. Add the following section to the “Inputdevice” section:

Section “Inputdevice” 
              Identifier “touchscreen1” 
              Driver “elographics” 
              Option “Device” “/dev/ttyS0” 
              Option “AlwaysCore” 
              Option “screenno” “0”
              Option “MinX”  “600” 
              Option “MaxX”  “3600” 
              Option “MinY”  “600” 
              Option “MaxY”  “3600” 
              Option “UntouchDelay” “3” 
              Option “ReportDelay” “1” 
EndSection

4. Save changes to the XF86Config-4 file.

For Redhat Linux 8.0
 
Edit the Configuration File

1. Edit the XF86Config file, normally found in the /etc/X11 directory.  The instructions below are for a touchscreen 
connected to COM one.  In step three below, Option “Device” “/dev/ttyS0” specifies the COM port the touchscreen 
is connected to.  Use Option “Device” “/dev/ttyS0” for COM one, Option “Device” “/dev/ttyS1” for COM two, Option 
“Device” “/dev/ttyS2” for COM three, and Option “Device” “/dev/ttyS3” for COM four.

2. Add the following line to the “ServerLayout” Section:

Inputdevice  “touchscreen1” “SendCoreEvents”

3. Add the following section to the “Inputdevice” section:

Section “Inputdevice” 
              Identifier “touchscreen1” 
              Driver “elographics” 
              Option “Device” “/dev/ttyS0” 
              Option “AlwaysCore” 
              Option “screenno” “0”
              Option “MinX”  “600” 
              Option “MaxX”  “3600” 
              Option “MinY”  “600” 
              Option “MaxY”  “3600” 
              Option “UntouchDelay” “3” 
              Option “ReportDelay” “1” 
EndSection

4. Save changes to the XF86Config file.

Restart X
 
1. If you configured your system to start X automatically, restart X by pressing Ctrl, Alt, Backspace.  If you 
configured your system to start in a command line mode, type “startx” at the command line prompt.  The 
touchmonitor should automatically be identified and the driver installed.  Complete the steps in the Touchscreen 
Calibration section for accurate video to touch alignment.


Touchscreen Calibration

For Redhat Linux 7.1 and 7.2, the default calibration values in the XF86Config-4 file are MinimumXPosition 600, 
MaximumXPosition 3600, MinimumYPosition 600, MaximumYPosition 3600.

For Redhat Linux 7.3, the default calibration values in the XF86Config-4 file are MinX 600, MaxX 3600, MinY 600, 
MaxY 3600.

For Redhat Linux 8.0, the default calibration values in the XF86Config file are MinX 600, MaxX 3600, MinY 600, 
MaxY 3600.

Whatever version of Linux you are using, the default calibration values need to be manually adjusted for the 
touchscreen to be calibrated.

1. On CRTs, adjust the video image size and position as desired.  The picture must lie within the touchscreen’s 
active area.  Using a felt-tip pen or dry marker, mark the video extremes in the corners.  The touchscreen must be 
calibrated to the position of the video image.  This step may not be necessary if you are using an LCD since the 
touchscreen active area should equal the display active area.

2. Boot the PC into DOS mode (booting from a DOS floppy if necessary).

3. Unzip the Elocallx.zip file.  Load the DOS touch driver, Elodev.exe, with the correct command for the model of 
controller you are using:
 
Elodev 2210,1,9600 — if you are using a 2210 controller on COM1 
Elodev 2210,2,9600 — if you are using a 2210 controller on COM2 
Elodev 2310,1,9600 — if you are using a 2310 controller on COM1 
Elodev 2310,2,9600 — if you are using a 2310 controller on COM2 
Elodev 2500,1,9600 — if you are using a 2500S controller on COM1 
Elodev 2500,2,9600 — if you are using a 2500S controller on COM2
Elodev 4000,1,9600 — if you are using a 4000S controller on COM1 
Elodev 4000,2,9600 — if you are using a 4000S controller on COM2

If you are using COM three or above type Elodev at the command prompt for the correct Elodev command line 
usage.

Once you see “Elodev installed”, go to the next step.

4. Start the DOS calibration routine by typing: Elocallx

5. Select the video resolution (VGA, SVGA, etc.) that X Windows will be using with the cursor keys and then press 
the “Enter” key.  The video mode will change.

6. Verify that the video image size and position is identical with the markings.

7. Press ‘C’ to calibrate in this video mode

8. From a position of normal use, touch the three targets as they appear.

9. Press ‘S’ to exit the calibration program.

10. Write down the values of XLow, XHi, YLow and YHi.  For example, XLow=567, XHi=3629, YLo=740, YHi=3661

11. Reboot the Linux operating system.  Edit the configuration file used by your system, whether XF86Config or 
XF86Config-4, and insert the values output by Elocallx, where: 

MinX or MinimumXPosition=XLow 
MaxX or MaximumXPosition=XHi 
MinY or MinimumYPosition=YLow 
MaxY or MaximumYPosition=YHi 

12. If you configured your system to start X automatically, restart X by pressing Ctrl, Alt, Backspace.  If you 
configured your system to start in a command line mode, type startx at the command line prompt.

Troubleshooting

1. To verify that the touchmonitor is connected correctly to the PC and that it is functioning correctly, type the 
following command in an X terminal window:
 
od -h -w10 </dev/ttyS0 — This is for COM1 
od -h -w10 </dev/ttyS1 — This is for COM2

Touch the screen and you should see a group of numbers scrolling across the screen.

Screen Orientation Issues

Touchscreens are typically designed to be mounted to a display with a specific orientation so that calibration values 
will increase from left to right for the X-axis and from bottom to top for the Y-axis.  If the design of the touchscreen 
being used does not meet this criteria, is mounted so that it does not meet this criteria, or the touchscreen cable is 
connected backwards, cursor position will not match the position touched.  A typical symptom of this kind of 
problem after calibrating the touchscreen would be to touch one side of the touchscreen and the cursor would 
appear on the opposite side of the display.  The public driver does not include code to handle screen orientation 
issues.  To correct this problem, swap the MinX and MaxX values, and the MinY and MaxY values in the 
Inputdevice section of the Configuration file (Minimum/MaximumX/YPosition for earlier versions). 


To contact Elo technical support, see www.elotouch.com/support/tech.asp.



