BRLTTY Driver for the Tieman Voyager Braille Display

Authors:
Stphane Doyon  <s.doyon@videotron.ca>
Stphane Dalton <sdalton@videotron.ca>

This driver supports the Tieman Voyager 44 and 70.

Many thanks to the Tieman people: Corand van Strien, Ivar Illing, Daphne
Vogelaar and Ingrid Vogel. They provided us with a Braille display (as
well as programming information) so that we could write this driver. They
replaced the display when it broke and they answered our technical
questions. It is very motivating when companies take an interest in such
projects and are so supportive.

Thanks to Andor Demarteau <ademarte@students.cs.uu.nl> who got this whole
project started and beta-tested all our early buggy attempts.

This is the first release of this driver. It seems to work very well but
it may still need some work. I have chosen the key bindings somewhat
quickly, and also I have never used Tieman's software for the Voyager so
I do not know what key bindings users may be used to. So key bindings may
need to be reworked.

When BRLTTY will be running, press the leftmost routing key to bring up
the help screen so you can read the details of the key bindings.

Other BRLTTY drivers are typically "stand alone" in the sense that they
can just open a serial port and talk directly to the display. However the
Voyager display connects through USB, so this driver must rely on a
kernel module to talk to the display.

Therefore you must also compile and install the kernel module found in
the kernel/ subdirectory: see kernel/README.

The kernel module implements a character device file which this driver
uses to talk to the kernel module. Use "make install-device" from THIS
directory to create that device file. Alternatively you can use mknod and
create a character device file with major 180 and the minor indicated in
kernel/voyager.h (currently 144). We suggest the name /dev/voyager.

You must tell BRLTTY to use that device file as the braille device. To do
this, edit the top-level BRLTTY Makefile and change
BRLDEV = /dev/ttyS0
to
BRLDEV = /dev/voyager
(alternatively use the braille-device parameter in your BRLTTY
configuration file).

Before you start BRLTTY, you will need to insert the kernel module. Do:
/sbin/modprobe voyager
Do not forget this command if you intend to modify your boot scripts to
start BRLTTY automatically.

Look in /var/log/messages for confirmation or error messages.

This driver knows four parameters, which you can pass using the
braille-parameters clause in your BRLTTY configuration file. They control
the repeat rate of some keys (only a few keys actually do repeat when
they are held). They are:
-"repeat_init_delay": delay in milliseconds before some movement key
   starts to repeat.
-"repeat_inter_delay": Delay in milliseconds between each repetition
   of movement keys.
-"dots_repeat_init_delay" and "dots_repeat_inter_delay": Same thing but
   for typed braille dots.
The default values (given in brlconf.h) seem fine, but if you want to
change them, place a line like this in your brltty.conf:
braille-parameters repeat_init_delay=300,repeat_inter_delay=150

There is only a handful of BRLTTY users, so if you are trying out this
driver, please drop us a note, even if you have no problems!

Note to BRLTTY developers: This is my first attempt at combining the key
binding definitions with the help file text in one place, through
annotations in the brl.c file. If you change the key bindings, currently
you need python installed to be able to rebuild the help files.
