Configuration parameters for mtouch

The following are valid parameters that can be configured under the mtouch section:

Parameter Description Type Possible Value(s)

The touch driver loaded by Screen.


If you configure your driver to be devi, you must ensure that you have the following processes running before starting screen:

  • devi-hid -R width,height touch where width and height define the resolution of your display. (e.g., devi-hid -R1280,720 touch))
  • io-hid -dusb (this is the case for configuring a multitouch display that uses USB for the control.)

For more information about the devi-hid and io-hid utilities, see its entry in the OS Utilities Reference.

To be able to successfully run io-hid and devi-hid, you must ensure that you have the following libraries in your LD_LIBRARY_PATH environment variable:

Use the following command on your target to get more information on the options when running devi-hid:
use devi-hid

There is no such requirement if you are using the egalax driver, as this driver will communicate directly with the hardware.

  • devi
  • egalax
options The options configuration is driver-dependent. The string you configure is passed verbatim to the driver itself. It can be used to set the height and width (in pixels) of a rectangular mtouch surface. Typcially, you set this to your display resolution (i.e., the configuration you used for the video-mode under the display section). This configuration must be in the form of: height=display_height ,width=display_width. For example, options = height=720,width=1280. string  

The full pathname of the server-side scaling configuration file that defines the scaling to apply to the touch coordinates. For an example of what a scaling configuration file must look like, see "Sample scaling.conf configuration file".

You must define a mode for the touch coordinates using a scaling.conf configuration file; you can define only one mode per configuration. The mode recommended is the scale mode configured with the resolution of your display. For example, your entry in the scaling.conf file would be:


string NULL(default)
min_event_interval The sampling rate (in microseconds) of the touch controller. You will not get two touch samples within a time less than that configured here. The effectiveness of this configuration is driver-dependent. unsigned long integer  
display The connection type to the display that is associated with the mtouch device. If the configuration is an integer, Screen will interpret the integer as the identifier of the display to be associated with the mtouch device; otherwise, if the configuration is a string that matches one of the valid display connection types, then Screen will associate the first display of that type with the mtouch device. string or integer
  • internal
  • composite
  • svideo
  • YPbPr
  • rgb
  • rgbhv
  • dvi
  • hdmi
  • 1..2