196 lines
7.2 KiB
Text
196 lines
7.2 KiB
Text
This file tells how to use gpm and X with a Gunze touchscreen.
|
|
|
|
It is pretty similar to README.microtouch, and I plan to unify them as
|
|
soon as I port the two implementation to offer a consistent look and
|
|
feel. Currently the Gunze implementation is more configurable but has
|
|
a worse calibration management (it must write to
|
|
/etc/gpm-calibration).
|
|
|
|
DEVICE CONFIGURATION
|
|
--------------------
|
|
|
|
The gpm decoder requires the Gunze device to be in Gunze Mode (not in
|
|
Elo Emulation Mode). The supported serial speeds are 9600 and 19200
|
|
baud, the latter being the default speed (in other words, to decode
|
|
data at 9600 you must use the "-b 9600" option of gpm; no "-b" option
|
|
selects 19200 baud). Currently, the only device supported is the
|
|
10-bit one.
|
|
|
|
USER INTERFACE
|
|
--------------
|
|
|
|
The decoder currently implemented in gpm is quite simple: it only
|
|
supports mouse motion and button-1 events. This will soon change: I
|
|
plan to implement corner-taps for button-2 and button-3, as well as a
|
|
different "mode" where motion is not supported and any touch event is
|
|
converted to a button-1 click.
|
|
|
|
In the default (and only) mode, when a user touches the screen, the
|
|
decoder generates mouse motion events. Tapping on the screen generates
|
|
button-press (as well as drag and release) events.
|
|
|
|
A "tap" is a finger-down (or pen-down) event generated quickly after a
|
|
finger-up. A touch event is considered a "tap" if the lapse since the
|
|
last finger-up is less than or equal to the double-click interval (the
|
|
default is 250ms, and the value is chosen by specifying the "-i"
|
|
option of gpm). This means that you'll usually move the pointer to the
|
|
desired position and then tap on it.
|
|
|
|
Double-and triple clicks are easily generated by repeated tapping.
|
|
|
|
Since tapping is usually accompanied by a small movement, the decoder
|
|
will use the coordinates of the finger-up event for the button-press.
|
|
Further dragging will be relative to the tapping position (i.e., the
|
|
finger-up position). Moreover, the last coordinate pair received on
|
|
finger-up is discarded, because it usually is slightly offset (due to
|
|
the non-negligible area of the fingertip).
|
|
|
|
My own experience with the Gunze device, revealed that sometimes the
|
|
finger bounces, generating very fast finger-up/finger-down pairs. The
|
|
gpm decoder, therefore, ignores any quick succession of finger-up and
|
|
finger-down events. The default is to ignore any release-press pair if
|
|
the time lapse is less than 100ms (note, however, that this time lapse
|
|
is configurable).
|
|
|
|
|
|
GPM OPERATION
|
|
-------------
|
|
|
|
In order to run the touchscreen with gpm, you need to update the
|
|
/dev/mouse symbolic link to point to the right serial port; then
|
|
invoke gpm with a command line like
|
|
|
|
gpm -t gunze
|
|
|
|
If /dev/mouse is not updated to point to the touchscreen serial port,
|
|
use
|
|
gpm -t gunze -m /dev/ttyS0
|
|
or an equivalent command.
|
|
|
|
Unfortunately, there is currently no way to paste text, but I'll
|
|
implement corner-tapping to achieve that.
|
|
|
|
|
|
Gunze-specific Configuration
|
|
----------------------------
|
|
|
|
It is possible to specify device-specific options to gpm in order to
|
|
customize the behaviour of the Gunze decoder. The options are passed
|
|
as argument to the "-o" command line (reminiscent of the mount
|
|
command).
|
|
|
|
The following options are recognized:
|
|
|
|
smooth=
|
|
The decoder smooths mouse movements, to prevent the jumpy
|
|
behaviour that usually results from finger movement. The
|
|
default smoothin factor is 9, you can specify a different
|
|
value if you wish: "gpm -t gunze -o smooth=3" gives faster
|
|
(and more jumpy) motion, while "gpm -t gunze -o smooth=30"
|
|
gives a very slow feeling.x
|
|
|
|
debounce=
|
|
The option is used to specify the minimum time lapse, in
|
|
milliseconds between finger-up and finger-down events. Smaller
|
|
time intervals are discarded to achieve debouncing. Note that
|
|
the maximum time lapse is the one used for double-click
|
|
detection, and is specified with the "-i" command-line option,
|
|
common to every other mouse type.
|
|
|
|
|
|
Please note that more than one option can be specified, by using the
|
|
comma ``,'' as a separator. For example:
|
|
|
|
gpm -t gunze -o smooth=5,debounce=150
|
|
|
|
|
|
|
|
Calibration
|
|
-----------
|
|
|
|
To calibrate the touchscreen, use the program "gunze-setup" found in
|
|
the source tree of gpm. The gpm daemon must already be running in
|
|
order for the program to work flawlessly, as the program stops and
|
|
restarts gpm internally (it depends on gpm for correct serial port
|
|
initialization).
|
|
|
|
The calibration program uses either /dev/touchscreen (if available) or
|
|
/dev/mouse (otherwise) as the serial port to communicate with the
|
|
touchscreen. You'll need therefore to create a symlink for one of
|
|
those names before running "gunze-setup".
|
|
|
|
After calibration, the calibration values can be found in the file
|
|
/etc/gpm-calibration, but gpm must be restarted in order to be able to
|
|
read them. This can be construed as a bug, and avoiding to stop the
|
|
program is in my TODO list.
|
|
|
|
|
|
|
|
X OPERATION
|
|
-----------
|
|
|
|
In order to use the touchscreen in X, you should install in your
|
|
system the "Summa" module, as modified by Frank Holtz (the driver is
|
|
available from http://www.hof-berlin.de/tablet/tablet.html, as well as
|
|
in the gpm CVS tree and from gpm-1.18.2 in the gpm release as well).
|
|
|
|
The compiled module (xf86Summa.so) should go in the module directory
|
|
of your X server, usually /usr/X11/lib/modules, when it sits in the
|
|
right place, a proper XF86Config will arrange for its loading.
|
|
|
|
Gpm must run in repeater mode, with a command line like:
|
|
gpm -t gunze -Rsumma
|
|
, which instructs gpm to repeat packets according to the Summa protocol.
|
|
|
|
Then, you need to add the following sections to your XF86config:
|
|
|
|
Section "module"
|
|
Load "xf86Summa.so"
|
|
EndSection
|
|
|
|
Section "Xinput"
|
|
Subsection "SummaSketch"
|
|
Port "/dev/gpmdata"
|
|
DeviceName "touchscreen"
|
|
Mode Absolute
|
|
AlwaysCore
|
|
EndSubSection
|
|
EndSection
|
|
|
|
|
|
Moreover, you should disable the "Pointer" section. I used a trick
|
|
like this one:
|
|
|
|
Section "Pointer"
|
|
Protocol "MouseSystems"
|
|
Device "/dev/fifo"
|
|
EndSection
|
|
|
|
Where /dev/fifo is just a plain unused fifo ("mknod /dev/fifo p")
|
|
|
|
If, when calling ``startx'', it won't work with a message of ``Invalid
|
|
Subsection Name'', please check the previous error lines, as they
|
|
explain what is wrong. They usually look like:
|
|
|
|
(--) no ModulePath specified using default: /usr/X11R6/lib/modules
|
|
xf86Summa.so: Unknown error loading module
|
|
|
|
It is pretty clear, if your are careful in reading the messages (I am
|
|
not that careful, and lose half an hour in trying to figure out what
|
|
was wrong).
|
|
|
|
|
|
Calibration
|
|
-----------
|
|
|
|
To calibrate the touchscreen, use the program "gunze-setup" found in
|
|
the source tree of gpm (yes, it is the same program used for the text
|
|
mode). The gpm daemon must already be running in order for the
|
|
program to work flawlessly, as the program stops and restarts gpm
|
|
internally (it depends on gpm for correct serial port initialization).
|
|
|
|
The calibration program uses either /dev/touchscreen (if available) or
|
|
/dev/mouse (otherwise) as the serial port to communicate with the
|
|
touchscreen. You'll need therefore to create a symlink for one of
|
|
those names before running "gunze-setup".
|
|
|