man LCDd (Administration système) - LCDproc server daemon

NAME

LCDd - LCDproc server daemon

SYNOPSIS

LCDd [-hfiws] [-c <config>] [-d <driver>] [-a <addr>] [-p <port>] [-u <user>] [-w <time>] [-r <level>]

DESCRIPTION

LCDd is the server portion of LCDproc which listens to a certain port (normally 13666) and displays information on an LCD display. It works with several types and sizes of displays.

As of version 0.4.3 of LCDproc most settings are configured through the LCDd configuration file, which is normally /etc/LCDd.conf. Before running LCDd you should carefully read through that file and modify everything neccessary according to your needs. Otherwise you might encounter LCDd not running properly on your system.

To make full use of LCDd, a client such as lcdproc(1) is required.

OPTIONS

Available LCDd options are:

-h
Display this help screen
-c <config>
Use a configuration file other than /etc/LCDd.conf
-d <driver>
Add a driver to use (output only to first)
-f
Run in the foreground
-i
Disable showing of the main LCDproc server screen
-w <waittime>
Time to pause at each screen (in seconds)
-a <addr>
Network IP address to bind to
-p <port>
Network port to listen for connections on
-u <user>
User to run as
-s
Output messages to syslog
-r <level>
Report level (default=2)

Supported Drivers

Currently supported display drivers include:

CFontz (or CrystalFontz)
CrystalFontz LCD displays
curses (or ncurses)
Standard video display using the ncurses library
HD44780
Hitachi HD44780 LCD displays
BayRAD
EMAC BayRad displays
irmanin
IrMan infrared (input)
lircin
Infrared (input)
wirz-sli
Wirz SLI driver (unknown)
joy
Joystick driver (input)
MtxOrb (or MatrixOrbital)
Matrix Orbital displays (not Matrix Orbital GLK displays)
glk
Matrix Orbital GLK graphical LCD displays
LB216
LB216 LCD display
lcdm001 (or LCDM001)
kernelconcepts.de 20x4 serial LCD displays
text
Standard "hard-copy" text display
debug
Undocumented debug driver

Multiple drivers can be used simultaneously; thus, for example, a Matrix Orbital display (MtxOrb driver) can be combined with an infrared driver (irmanin driver).

INVOCATION

LCDd -d MtxOrb -d joy
As of version 0.4.3, driver parameters are read from a configuration file (default location /etc/LCDd.conf) rather than being passed on the command line as arguments. The invocation example above will start LCDd with the Matrix Orbital driver and the Joystick input driver, and attempt to load the driver parameters from the default configuration file.

SERVER PROTOCOL

There is a basic sequence:

1. Open a TCP connection to the LCDd server port (usually 13666).
2. Say "hello"
3. The server will return some information on the type
of display available.
4. Define (and use) a new screen and its widgets.
5. Close the socket when done displaying data.

There are many commands for the LCDd server:

hello
This starts a client-server session with the LCDd server; the server will return a data string detailing the type of display and its size.
client_set [-name #id]
Set the client's name, etc.
screen_add #id
Add a new screen to the display.
screen_del #id
Remove a screen from the display.
screen_set #id [-priority number] [-name my_name ] [-duration integer] [-wid width] [-hgt height] [-heartbeat mode]
Initialize a screen, or reset its data.
widget_add #screen #id type [-in #id]
Add a widget to screen #screen.
widget_del #screen #id
Delete widget #id from screen #screen.
widget_set #screen #id data
Set the data used to define a particular widget #id on screen #screen.

Heartbeat Modes

Valid heartbeat mode values (for the screen_set command) are:

on, heart
Display heart symbol.
normal, default
Normal display.
off, none
No heartbeat display.
slash
Display rotating slash display.

Priorities

Valid priority values (used in the screen_set command) are as follows:

0
This is rather extreme; don't do this!
1
Extremely important!
16
Emergency priority
32
Very high priority (important)
64
High priority (normal)
128
Normal (recommended)
192
Low priority (normal)
224
Very low priority (very unimportant)
240
Extremely low priority
255
This screen won't show up very much even if there are no other screens queued...

An example of how to properly use priorities is as follows:

Imagine you're making an mp3 player for lcdproc. When the song changes, it's nice to display the new name immediately. So, you could set your screen's priority to 64, wait for the server to display (or ignore) your screen, then set the screen back to 128. This would cause the mp3 screen to show up as soon as the one onscreen was finished, then return to normal priority afterward.

Or, let's say your client monitors the health of hospital patients. If one of the patients has a heart attack, you could set the screen priority to 16 (emergency), and it would be displayed immediately. It wouldn't even wait for the previous screen to finish. Also, the display would stay on screen most of the time until the user did something about it.

A priority of 1 would stay onscreen permanently, with flashing lights and other visual cues if possible. Using this priority is not recommended.

The duration can be either a positive number, or -1. A positive number (greater than zero) indicates how many display frames the screen should last. A 0 (zero) or -1 means that the server should use "auto" duration, which is probably a good idea. This will be whatever the user wants. It defaults to 4 seconds (32 frames), or will be a calculated value for things such as scrollers.

Widget Types

Widgets can be any of the following:

string
A text string to display (as is).
hbar
A horizontal bar graph.
vbar
A vertical bar graph.
title
A title displayed across the top of the display, within a banner.
icon
A graphic icon.
scroller
A scrolling text display, scrolling either horizontally or vertically.
frame
A container to contain other widgets, permitting them to be refered to as a single unit. A widget is put inside a frame by using the -in #id parameter, where #id refers to the id of the frame.

Widgets are drawn on the screen in the order they are created.

Setting Widget Data

In the widget_set command, the data argument depends on which widget is being set. Each widget takes a particular set of arguments which defines its form and behavior:

string
x y text
hbar
x y length_in_pixels
vbar
x y length_in_pixels
icon
x y binary_data
title
text
scroller
left top right bottom direction speed text The text defined will scroll in the direction defined. Valid directions are h (horizontal) and v (vertical). The speed defines how many "movements" (or changes) will occur per frame. A positive number indicates frames per movement; a negative number indicates movements per frame.
frame
left top right bottom wid hgt dir speed Frames define a visible "box" on screen, >from the (left, top) corner to the (right, bottom) corner. The actual data may be bigger, and is defined as wid (width) by hgt (height); if it is bigger, then the frame will scroll in the direction (dir) and speed defined.

BUGS

If LCDd seems to quietly disappear upon invocation or other similar problems, check the order of the options and the quoting involved. Some combinations of options will be misread and thus fail.

Try using the -d option last.

FILES

/etc/LCDd.conf, LCDd default configuration file

SEE ALSO

lcdproc()

AUTHOR

LCDd was originally written by William Ferrell (wwf@splatwerks.org) and Scott Scriv en (scriven@cs.colostate.edu).

Since that time various people have contributed to LCDproc.

The newest version of LCDd should be available from here as part of the lcdproc package:

http://lcdproc.omnipotent.net/

LEGAL STUFF

The lcdproc package is released as "WorksForMe-Ware". In other words, it is free, kinda neat, and we don't guarantee that it will do anything in particular on any machine except the ones it was developed on.

It is technically released under the GNU GPL license (you should have received the file, "COPYING", with LCDproc) (also, look on http://www.fsf.org/ for more information), so you can distribute and use it for free -- but you must make the source code freely available to anyone who wants it.

For any sort of real legal information, read the GNU GPL (GNU General Public License). It's worth reading.