Tslib

About

Tslib is an abstraction layer for touchscreen panel events, as well as a filter stack for the manipulation of those events. It was created by Russell King, of arm.linux.org.uk. Tslib is generally used on embedded devices to provide a common user space interface to touchscreen functionality.

Source Download Location

Visit tslib github

Cross compiling

• Run ./configure --prefix=(Abosolute path on NFS) --host=arm-linux-gnu.
• Edit the file config.h and comment the line "#define malloc rpl_malloc" to avoid this option:"#define malloc rpl_malloc" -> "//#define malloc rpl_malloc"
  • AC_FUNC_MALLOC in configure.ac seems to cause malloc to be defined to rpl_malloc, which is never implemented and therefore cause a link error.Removing this line from AC_FUNC_MALLOC is a workaround i got after browsing net.
• Issue make and make install.
• This will generate the ts_calibrate and ts_test executables.

Configuration(required for execution).

Make sure you have the following settings right(You can have them in your profile).

• export TSLIB_FBDEVICE=/dev/fb0
  • This is for the Fbdev device node to be used for display.
• export TSLIB_TSDEVICE=/dev/input/touchscreen0
• export TSLIB_CONFFILE=/etc/ts.conf

Execution

• First run ts_calibrate to calibrate the touch screen.
• You can now run ts_test application. This application helps in moving a cross-hair pattern around the LCD touchscreen. The pattern moves with your stylus movements. Also there is a draw option supported. Using your stylus you can write/draw on touchscreen.

Execution logs

The logs of ts_calibrate,ts_test run is provided below-

TS_READ----> x = 4, y = 306, pressure = 673
416.280517:     4    306    673
TS_READ----> x = 4, y = 306, pressure = 679
416.286407:     4    306    679
TS_READ----> x = 5, y = 308, pressure = 0
416.291717:     5    308      0

The logs mainly print the coordinate positions and pressure values according to the stylus movements on the touchscreen.