This article provides steps for how to fix a Linux machine when the calibration is inaccurate after rotating the screen

See below for information on inaccurate display orientation when rotating image on a Linux machine.

This is expected behavior. Whenever the display orientation is changed, then the touchscreen needs to be re-calibrated. Here is a link to our downloads page to download the driver needed for calibration: Elo Downloads .

There are also installation instructions on the page with the driver download. 

Step 6 in the installation guide covers calibrating the screen. 


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6. Calibrating the Touchscreen
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Important:
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Users must have read and write access to "/dev/elo-usb" and "/etc/opt/elo-usb" 
directories to perform the touchscreen calibration. All long command line 
options in elova calibration utility use the "--" format. (example: "--help")

Type "# /etc/opt/elo-usb/elova --help" for available command line parameters and 
usage.   


Step I:
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The calibration utility, by default, will perform an onboard calibration for 
supported controllers like 2701, 2218, etc. Onboard calibration process applies 
the computed calibration parameters directly to the touch controller and aligns 
the touch coordinates output from the controller. Hence, calibration retrieval 
process in Step 7 is not required, if the onboard calibration process has been 
completed successfully.

Run the calibration utility with root privileges from a command window in X 
Windows from the /etc/opt/elo-usb directory for a single or multiple video setup 
(supports Xorg Xinerama, Xorg non-Xinerama and Nvidia Twinview options). 

  # cd /etc/opt/elo-usb
  # sudo ./elova 

If the previous process based on the --nvram option is used to store the 
calibration data, then the calibration retrieval process in Step 7 is required.    

  # cd /etc/opt/elo-usb
  # sudo ./elova --nvram       

The '--nvram' option writes the calibration data to the Non Volatile RAM (if 
present) on the touchmonitor and the configuration file on the hard disk. To 
perform the calibration and update only the configuration file on the hard disk, 
for all touch controllers which do not support onboard calibration, use the 
command shown below.    

  # cd /etc/opt/elo-usb
  # sudo ./elova 


In a multiple video setup, the calibration target(s) will be shown on the first 
video screen and switch to the next video screen after a 30 second default 
timeout for each target or screen. Once the touchscreen is calibrated the data 
is stored in a configuration file on the hard disk. To display the calibration 
targets on just one specific video screen(example:videoscreen[1]) use the 
command shown below.

  # cd /etc/opt/elo-usb
  # sudo ./elova --videoscreen=1


To change or disable the default calibration timeout for each target or screen, 
use the command shown below. [Timeout Range: Min=0 (no timeout), Max=300 secs, 
Default=30 secs]

  # cd /etc/opt/elo-usb
  # sudo ./elova --caltargettimeout=0      
      Disable the calibration timeout for all targets and videoscreens 

  # sudo ./elova --caltargettimeout=45     
      Modify the calibration timeout to 45 seconds  


To view a list of video and USB touch devices available for calibration, use the 
command shown below.

  # cd /etc/opt/elo-usb
  # ./elova --viewdevices


To view all the available options and specific usage for elova calibration 
program, use the command shown below.

  # cd /etc/opt/elo-usb
  # ./elova --help


Step II:
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Touch the target(s) from a position of normal use. The calibration data is 
written to the driver at the end of calibration.