TS.CONF(5)                                                             tslib                                                            TS.CONF(5)

NAME

       ts.conf - Configuration file for tslib, controlling touch screens for embedded devices.

DESCRIPTION

       The idea of tslib is to have a core library that provides standardised services, and a set of plugins to manage the conversion and
       filtering as needed.

       The plugins for a particular touchscreen are loaded automatically by the library under the control of a static configuration file,
       /etc/ts.conf.  /etc/ts.conf gives the library basic configuration information. Each line specifies one module, and the parameters for that
       module. The modules are loaded in order, with the first one processing the touchscreen data first. For example:

             module_raw input
             module variance delta=30
             module dejitter delta=100
             module linear

MODULE PARAMETERS

       variance
           Tries to do it's best in order to filter out random noise coming from touchscreen ADC's. This is achieved by limiting the sample
           movement speed to some value (e.g. the pen is not supposed to move quicker than some threshold).

           This is a 'greedy' filter, e.g. it gives less samples on output than receives on input.

           o   Parameters: delta.

               Set the squared distance in touchscreen units between previous and current pen position (e.g. (X2-X1)^2 + (Y2-Y1)^2). This defines
               the criteria for determining whenever two samples are 'near' or 'far' to each other.

               If the distance between previous and current sample is 'far', the sample is marked as 'potential noise'. This doesn't mean yet that
               it will be discarded; if the next reading will be close to it, this will be considered just a regular 'quick motion' event, and it
               will sneak to the next layer. Also, if the sample after the 'potential noise' is 'far' from both previously discussed samples, this
               is also considered a 'quick motion' event and the sample sneaks into the output stream.

       dejitter
           Removes jitter on the X and Y co-ordinates. This is achieved by applying a weighted smoothing filter. The latest samples have most
           weight; earlier samples have less weight. This allows to achieve 1:1 input->output rate.

           o   Parameters: delta.

               Squared distance between two samples ((X2-X1)^2 + (Y2-Y1)^2) that defines the 'quick motion' threshold. If the pen moves quick, it
               is not feasible to smooth pen motion, besides quick motion is not precise anyway; so if quick motion is detected the module just
               discards the backlog and simply copies input to output.

       linear
           Linear scaling module, primarily used for conversion of touch screen co-ordinates to screen co-ordinates.

           o   Parameters: xyswap.

               Interchange the X and Y co-ordinates -- no longer used or needed if the new linear calibration utility ts_calibrate is used.

ENVIRONMENT VARIABLES

       Latest versions of the Xorg tslib input driver use hal to configure the touchscreen within Xorg. Environment variables are only needed for
       the tslib commands.

       TSLIB_TSDEVICE
           If the default touchscreen device cannot be found, set the TSLIB_TSDEVICE environment variable to the touchscreen device to use.

           Default: /dev/input/event0

       TSLIB_CONSOLEDEVICE
           Tslib default console device.

           Default: /dev/tty

       TSLIB_CALIBFILE
           Stores calibration data obtained using ts_calibrate.

           Default: /etc/pointercal

       TSLIB_CONFFILE
           Set a different location for the ts.conf configuration file itself.

           Default; /etc/ts.conf.

       TSLIB_FBDEVICE
           Framebuffer device to use for the touchscreen support.

           Default: /dev/fb0.

       TSLIB_PLUGINDIR
           Plugin directory for tslib.

           Default: /usr/lib/$triplet/ts0/ where triplet is the MultiArch path, e.g. arm-linux-gnueabi.

AUTHOR

       This manual page was written by Neil Williams codehelp@debian.org for the Debian(TM) distribution because the original program does not
       have a manual page, but may be used by others. Permission is granted to copy, distribute and/or modify this document under the terms of the
       GNU General Public License, Version 2 any later version published by the Free Software Foundation.

       On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL.

AUTHOR

       Russell King
           Author.

COPYRIGHT

       Copyright (C) 2008 Neil Williams

Debian 5                                                   Wed 06 Aug 2008 10:46:33 ART                                                 TS.CONF(5)