Hardware Reference
In-Depth Information
If this has worked you should see only the program's license print to the screen with no errors printed to your
terminal. Now take a look at your LCD: you should see a welcome message followed by the client and server count
being displayed. If you don't see this, you have errors; revisit your config file. If no errors appeared, kill the process
and start it as a service:
# service LCDd start
Don't forget to run the following if you want the service to start on boot:
# chkconfig LCDd on
Alright, the server is up and running. Now what? How can you make it do something? This is one of the best
features of
lcdproc
. You now have many choices for clients and where that client will run. You recall from the
LCDd.conf
file that you configured an IP address and this sets up
LCDd
to listen on the set IP and port. This allows you
to run your LCD client from anywhere on the same subnet. You could run it on the Raspberry Pi or you could run
it on another desktop. You can even sample data from the client running on the remote machine and send it to the
Raspberry Pi's
LCDd
server to display.
Running a Client
For a quick test I will use the built-in client called
lcdproc
; you can find its configuration file at
/etc/sysconfig/
lcdproc/lcdproc.conf
. This file has a similar style as the
LCDd.conf
file you configured before. This file is broken up
into two main sections:
•
One is called
[lcdproc]
.
The other sections are all called screens. A screen is what will appear on the physical LCD
•
when you run the client; it may look like
[cpu]
, for example.
You're going to need to set only one option to allow the
lcdproc
client to communicate with the
LCDd
server. In
the
[lcdproc]
section, search for the option called
server
and change this to be the host where
LCDd
is running. In my
case I set this IP address to be the IP of the Raspberry Pi. Do note that
localhost
won't work in this scenario as you
have bound the
LCDd
server to a set IP address rather than localhost or the wildcard address.
Take a look at the screens section next. Each screen may or may not have configuration options; read though the
comments to see what each option will do for each screen. There is one setting that is common across all screens and
that setting is called
Active
. If the screen has the
Active
setting set to
True
, the
LCDd
server will display this screen
on your LCD. If you set this value to
Active=false
, the screen will no longer be displayed on your LCD. Now that you
have a basic
lcdproc.conf
file set up, it's a wise idea to test it. Ensure that
LCDd
is running; if it's not,
lcdproc
will throw
an error about not being able to connect to the specified host. To test the
lcdproc
client, run the following command:
# lcdproc -f
This should give you no feedback if it's working correctly. Now take a look at your LCD; you can see the screens
you defined in the
lcdproc.conf
file scrolling across the LCD. You can now start this as a service if you like. Or if you
feel the default
lcdproc
client is a little limited, then take a look at a list of clients on
http://lcdproc.org/clients.php3
.
If none of the clients are suitable, you may want to write your own.
■
the
LCDd
server protocol accepts clear text messages; take a look at the development guide at
http://lcdproc.sourceforge.net/docs/lcdproc-0-5-5-dev.html
. this guide will show you how to write a client.
it's not as hard as it sounds; like i said, the
LCDd
server speaks in clear text.
Note
