Tslib

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Library which provides a common interface to touchscreen and allows touchscreen events filtering or calibrating...

Installation

Tslib is now installed by default on Armadeus SDK. For reference, installation instructions are kept here.

Configuration details

Most are now automatically done in recent Armadeus SDK releases. If you are interested, history is kept here.

Note Note: to work, Tslib requires that the corresponding touchscreen Linux driver has been loaded before. On APF9328/APF27, please have a look to TSC2102_Linux_driver if not already done. On APF51(Wolfson) / APF28(internal) / APF6Dev(SX8654) driver is statically built inside Linux kernel and should auto detect the touchscreen controller.


Config file

  • Tslib plugins can be tuned with /etc/ts.conf. A default one is provided in all rootfs:
 # cat /etc/ts.conf
 
 module_raw input
 module pthres pmin=1
 module variance delta=30
 module dejitter delta=100
 module linear

Envt variables

  • Some ENVT variables are needed too. By default they are defined in /etc/profile:
 export TSLIB_TSDEVICE=/dev/input/event0
 export TSLIB_TSEVENTTYPE=INPUT
 export TSLIB_CONFFILE=/etc/ts.conf
 export TSLIB_CALIBFILE=/etc/pointercal
  • If you have other input devices (like mouse or keyboard) and they have been detected by Linux before your touchscreen device, then you will probably need to adapt TSLIB_TSDEVICE variable.

Calibration

  • Before first usage, a touchscreen needs to be calibrated. When starting, Tslib will look at /etc/pointercal to get calibration data. This file is created when running Tslib's calibration tool:
 # /usr/bin/ts_calibrate

Tslib calibrate.png

Testing it

# /usr/bin/ts_test

Tslib test.png

Adding Tslib support to SDL

SDL is by default compiled with Tslib support in current Buildroot distribution. You just have to make SDL knows the presence of Tslib when launching your application with:

 export SDL_MOUSEDRV=TSLIB
 export SDL_MOUSEDEV=$TSLIB_TSDEVICE

To have an example of a SDL application using Tslib, take a look at target/demos/backlight_control/ sources.

Adding Tslib support to Qt

When selecting Qt in Buildroot menuconfig you can choose the input method to be Tslib. See Qt installation for more informations.

Links