Scroll to navigation

LCDd(8) LCDproc suite LCDd(8)


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 daemon 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 overridden using command line options. Before running LCDd you should carefully read through that file and modify everything necessary 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:

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.
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 LCD modules by EMAC Inc.
CrystalFontz CFA-632 and CFA-634 serial LCD displays
CrystalFontz CFA-533, CFA-631, CFA-633 and CFA-635 serial/USB LCD displays
Standard video display using the (n)curses library
serial/USB displays by Cwlinux (
VFD front panel display on Aopen XC Cube EA65 media barebone
LCD display on the EyeboxOne
The Futaba TOSD-5711BB VFDisplay on Elonex Artisan/Scaleo Media Centre PCs
LCD display on the Logitech G15 keyboard
generic driver for graphical LCDs with FreeType rendering support. This driver supports the following sub-drivers (a.k.a. connection types):
Till Harbaum's open source/open hardware GLCD2USB (
picoLCD 256x64 Sideshow graphic LCD (
Write out screens as PNG images
Uses serdisplib ( for output
Toshiba T6963 based LCD displays (graphic mode)
graphical LCDs supported by graphlcd-base
Matrix Orbital GLK Graphic Displays
Hitachi HD44780 LCD displays. This driver supports the following sub-drivers (a.k.a. connection types):
LCD 4bit-mode, connected to a PC parallel port
LCD 8bit-mode, connected to a PC parallel port
LCD in 4bit-mode through a 4094 shift register
LCD in 8bit-mode using WinAmp-wiring, connected to a PC parallel port
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 serial port
???, connected to a serial port
VDR-Wake module by Frank Jepsen (
Pertelian X2040 module (
LIS2 from VLSystem (, connected to USB
MPlay Blast from VLSystem (, connected to USB
LCD device from Adams IT Services (
USB-to-HD44780 converter by BWCT (
Till Harbaum's open source/open hardware LCD2USB (
Devices based on Dick Streefland's USBtiny firmware
USS-720 USB-to-IEEE 1284 Bridge (Belkin F5U002 USB Parallel Printer Adapters)
Sprut's open source / open hardware USB-4-all (
USB connection via a FTDI FT2232D chip in bitbang mode
LCD in 4-bit mode driven by PCF8574(A) / PCA9554(A), connected via I2C bus
Adafruit RGB Positive 16x2 LCD+Keypad for Raspberry Pi
LCD with KS0073 or equivalent in serial mode, connected via SPI bus
PiFace Control and Display for the Raspberry Pi (
TCP connection using open source/open hardware ethlcd (
LCD driven by the GPIO pins of a Raspberry Pi
LCD connection via GPIO pins controlled by the linux sysfs interface
140x32 pixel VFD Display of the Intra2net Intranator 2500 appliance
ICP Peripheral Communication Protocol alarm/LCD board used in QNAP devices and 19" rack cases made by ICP
iMON IR/VFD modules in cases by Soundgraph/Ahanix/Silverstone/Uneed/Accent
iMON IR/LCD modules in cases by Soundgraph/Ahanix/Silverstone/Uneed/Accent/Antec
IRTrans IR/VFD modules in cases by Ahanix (e.g. MCE303) and possibly others May require irserver ( to be running for connectivity.
Code Mercenaries IOWarrior
IrMan infrared (input)
Joystick driver (input)
LB216 LCD displays 20x4 serial LCD displays
serial LCD terminal from Helmut Neumark Elektronik (
Linux event devices (input)
Infrared (input)
L.I.S MCE 2005 20x2 VFD (
VFD displays in Medion MD8800 PCs
Futuba MDM166A displays
MSI-6931 displays in 1U rack servers by MSI
MTC_S16209x LCD displays by Microtips Technology Inc
Matrix Orbital displays (except Matrix Orbital GLK displays)
LCD display on the Logitech MX5000 keyboard
Noritake VFD Device CU20045SCPB-T28A
Olimex MOD-LCD1x9 14 segment display
Dumps the entire framebuffer to the serial port at a configurable rate. USB LCD (PicoLCD 20x4 & picoLCD 20x2)
LCD displays from Pyramid (
Watchguard Firebox LCD display based on SDEC LMC-S2D20 (
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)
Wirz SLI driver (unknown)
STV5730A on-screen display chip
LCD devices from SURE electronics (
VGA monitors using svgalib
Toshiba T6963 based LCD displays (text mode)
Standard "hard-copy" text display
LCD module in Tyan Barebone GS series
ULA-200 device from ELV (
VFD/IR combination in case MonCaso 320 from Moneual
yard2 LCD module
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.


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:

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.
Set the client's name.
Add a new screen to the display.
Remove a screen from the display.
Initialize a screen, or reset its data.
Add a widget of type type to screen #screen.
Delete widget #id from screen #screen.
Set the data used to define a particular widget #id on screen #screen.


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

Display pulsing heart symbol.
No heartbeat display.
Use client's heartbeat setting. This is the default.


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

Turn backlight on.
Turn backlight off
Turn backlight off when it is on and vice versa.
Use client's backlight setting. This is the default.
Blinking backlight
Flashing blacklight


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

The client is doing interactive input.
The screen has an important message for the user.
an active client
Normal info screen, default priority.
The screen is only visible when no normal info screens exists.
The screen will never be visible.

For compatibility with older versions of clients a mapping of numeric priority values is also supported:

1 - 64
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:

A text string to display (as is).
A horizontal bar graph.
A vertical bar graph.
A title displayed across the top of the display, within a banner.
A graphic icon.
A scrolling text display, scrolling either horizontally or vertically.
A container to contain other widgets, permitting them to be referred 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.
Displays a large decimal digit

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


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).
title text
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 speed defined.
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 line:

LCDd -f -r 5 -s 0


/etc/LCDd.conf, LCDd's default configuration file


lcdproc-config(5), lcdproc(1), lcdexec(1)


Many people have contributed to LCDd. See the CREDITS file for more details.

All questions should be sent to the lcdproc mailing list. The mailing list, and the newest version of LCDproc, should be available from here:


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 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.

February 10, 2014 LCDproc