LCDd - LCDproc server daemon
LCDd [-hf] [-c config] [-d driver] [-i bool] [-a addr] [-p port] [-u
user] [-w time] [-r level] [-s bool]
LCDd is the server part of LCDproc, a deamon which listens to a certain
port (normally 13666) and displays information on an LCD display. It
works with several types and sizes of displays.
Most settings of LCDd are configured through its configuration file
/etc/LCDd.conf, some of them can be overriden using command line
options. 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), lcdexec(1), or
lcdvc is required.
Available options are:
-h Display help screen
Use a configuration file other than /etc/LCDd.conf
Specify a driver to use (output only to first), overriding the
Driver parameter in the config file’s [Server] section.
-f Run in the foreground, overriding the Foreground parameter in
the config file’s [Server] section. The default, if not
specified in the config file, is to daemonize LCDd as it is
intended to operate in the background.
Tell whether the to enable (1) or disable (0) showing the
LCDproc server screen in n the screen rotation, overriding
ServerScreen in the config file’s [Server] section.
Time to pause at each screen (in seconds), overriding the
WaitTime parameter in the config file’s [Server] section.
Bind to network address addr, overriding the Bind parameter in
the config file’s [Server] section.
Listen on port port for incoming connections, overriding the
Port parameter in the config file’s [Server] section.
Run as user user, overriding the User parameter in the config
file’s [Server] section.
Output messages to syslog (1) or to stdout (0), overriding the
ReportToSyslog parameter in the config file’s [Server] section.
Set reporting level to level, overriding th ReportLevel
parameter in the config file’s [Server] section.
Currently supported display drivers include:
bayrad BayRAD LCD modules by EMAC Inc.
CFontz CrystalFontz CFA-632 and CFA-634 serial LCD displays
CrystalFontz CFA-633 serial/USB LCD displays
CrystalFontz CFA-631, CFA-633 and CFA-635 serial/USB LCD
curses Standard video display using the (n)curses library
CwLnx serial/USB displays by Cwlinux (http://www.cwlinux.com)
ea65 VFD front panel display on Aopen XC Cube EA65 media barebone
LCD display on the EyeboxOne (http://www.rightvision.com)
g15 LCD display on the Logitech G15 keyboard
graphical LCDs supported by graphlcd-base
glk Matrix Orbital GLK Graphic Displays
Hitachi HD44780 LCD displays. This driver supports the
following sub-drivers (a.k.a. connection types):
4bit LCD 4bit-mode, connected to a PC parallel port
8bit LCD 8bit-mode, connected to a PC parallel port
LCD in 4bit-mode through a 4094 shift register
winamp LCD in 8bit-mode using WinAmp-wiring, connected to a PC
LCD driven by a PIC-an-LCD chip/board by Dale Wheat,
connected to a serial port
LCD driven by a PIC16C54-based piggy-back board,
connected to a serial port
LCD driven by an Atmel AVR based board, connected to a
???, connected to a serial port
VDR-Wake module by Frank Jepsen
Pertelian X2040 module (http://pertelian.com/)
lis2 LIS2 from VLSystem (http://www.vlsys.co.kr), connected to
mplay MPlay Blast from VLSystem (http://www.vlsys.co.kr),
connected to USB
USB-to-HD44780 converter by BWCT (http://www.bwct.de)
Till Harbaum’s open source/open hardware LCD2USB
uss720 USS-720 USB-to-IEEE 1284 Bridge (Belkin F5U002 USB
Parallel Printer Adapters)
i2c LCD in 4-bit mode driven by PCF8574(A) / PCA9554(A),
connected via I2C bus
ftdi USB connection via a FTDI FT2232D chip in bitbang mode
ethlcd TCP connection using open source/open hardware ethlcd
usblcd LCD device from Adams IT Services (http://www.usblcd.de/)
140x32 pixel VFD Display of the Intra2net Intranator 2500
ICP A106 alarm/LCD board in 19" rack cases by ICP
imon iMON IR/VFD modules in cases by
iMON IR/LCD modules in cases by
IRTrans IR/VFD modules in cases by Ahanix (e.g. MCE303) and
possibly others May require irserver
(http://www.irtrans.de/en/download/linux.php) to be running for
Code Mercenaries IOWarrior
irman IrMan infrared (input)
joy Joystick driver (input)
lb216 LB216 LCD displays
kernelconcepts.de 20x4 serial LCD displays
lcterm serial LCD terminal from Helmut Neumark Elektronik
lirc Infrared (input)
lis L.I.S MCE 2005 20x2 VFD (http://vlsys.co.kr)
MD8800 VFD displays in Medion MD8800 PCs
ms6931 MSI-6931 displays in 1U rack servers by MSI
MTC_S16209x LCD displays by Microtips Technology Inc
MtxOrb Matrix Orbital displays (except Matrix Orbital GLK displays)
mx5000 LCD display on the Logitech MX5000 keyboard
Noritake VFD Device CU20045SCPB-T28A
Mini-box.com USB LCD (PicoLCD 20x4 & picoLCD 20x2)
LCD displays from Pyramid (http://www.pyramid.de)
SED1330/SED1335 (aka S1D13300/S1D13305) based graphical displays
122x32 pixel graphic displays based on SED1520 controllers
Driver for Point Of Sale ("POS") devices using various protocols
(currently AEDEX only)
Text VFDs of various manufacturers, see LCDproc user-
documentation for further details.
Shuttle VFD (USB-based)
sli Wirz SLI driver (unknown)
STV5730A on-screen display chip
svga VGA monitors using svgalib
t6963 Toshiba T6963 based LCD displays
text Standard "hard-copy" text display
tyan LCD module in Tyan Barebone GS series
ula200 ULA-200 device from ELV (http://www.elv.de)
xosd On Screen Display on X11
Multiple drivers can be used simultaneously; thus, for example, a
Matrix Orbital display (MtxOrb driver) can be combined with an infrared
driver (irmanin driver).
LCDd -d MtxOrb -d joy
The invocation example above will start LCDd reading its configuration
from the default configuration file /etc/LCDd.conf but overriding the
drivers specified therein with the Matrix Orbital driver and the
Joystick input driver.
LCDPROC CLIENT-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 client to send to 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 name
Set the client’s name.
Add a new screen to the display.
Remove a screen from the display.
screen_set #id [-name name ] [-wid width] [-hgt height] [-priority
prio] [-duration int] [-timeout int] [-heartbeat mode] [-backlight
mode] [-cursor mode] [-cursor_x xpos] [-cursor_y ypos]
Initialize a screen, or reset its data.
widget_add #screen #id type [-in #frame]
Add a widget of type type 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
Valid heartbeat mode values (for the screen_set command) are:
on Display pulsing heart symbol.
off No heartbeat display.
open Use client’s heartbeat setting. This is the default.
Valid heartbeat mode values (for the screen_set command) are:
on Turn backlight on.
off Turn backlight off
toggle Turn backlight off when it is on and vice versa.
open Use client’s backlight setting. This is the default.
blink Blinking backlight
flash Flashing blacklight
Valid priority settings (used in the screen_set command) are as
input The client is doing interactive input.
alert The screen has an important message for the user.
an active client
info Normal info screen, default priority.
The screen is only visible when no normal info screens exists.
hidden The screen will never be visible.
For compatibility with older versions of clients a mapping of numeric
priority values is also supported:
1 - 64 foreground
65 - 192
193 - (infinity)
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 foreground, wait for the server to
display (or ignore) your screen, then set the screen back to normal.
This would cause the mp3 screen to show up as soon as the one on screen
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 alert, 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.
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
icon A graphic icon.
A scrolling text display, scrolling either horizontally or
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
num Displays a large decimal digit
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
Displays text at position (x,y).
Uses text as title to display.
hbar x y length
Displays a horizontal bar starting at position (x,y) that is
length pixels wide.
vbar x y length
Displays a vertical bar starting at position (x,y) that is
length pixels high.
icon x y name
Displays the icon name at position (x,y).
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
num x int
Displays large decimal digit int at the horizontal position x,
which is a normal character x coordinate on the display. The
special value 10 for int displays a colon.
If LCDd seems not to work as expected, try to run it in the foreground
with reporting level set to maximum and reporting to stderr. This can
be achieved without changes to the config file by using the command
LCDd -f -r 5 -s 0
/etc/LCDd.conf, LCDd’s default configuration file
lcdproc-config(5), lcdproc(1), lcdexec(1)
LCDd was originally written by William Ferrell (email@example.com) and
Scott Scriven (firstname.lastname@example.org).
Since that time various people have contributed to LCDproc.
The newest version of LCDd should be available from here as part of the
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.