Adding a LCD display to a ClarkConnect server

Adding an LCD display to your ClarkConnect server is very easy. This project assumes you have basic soldering skills and a working knowledge of command-line linux. If your not handy with a soldering iron, and don't care to learn, you can purchase a kit. The LCD for this project is driven by LCD4Linux software.







Hardware

You are going to need a Hitachi HD44780 compatible module. These modules are available in different colors and sizes from many sources. I purchased mine from 411 Technology Services and have nothing but good things to say about them. 411 Technology includes a CD with every order with software, diagrams, specs, and schematics that are very helpful.

I am not going to "re-invent the wheel" here and instruction on hardwiring the module is available from several websites. I followed the instruction provided by Overclockers Austrailia with a few personal modifications. If the soldering scares you then purchase the kit I mentioned earlier which has the added benefit of a frame designed to fit into a drive bay.

Before you continue, make sure you plug the module into the computer to test to see if it is working. When you plug the assembly into the parallel port your display should show a series of horizonal bars. This is a sign your wiring is correct and the display is not dead.


Software

From the command prompt:

apt-get update
apt-get install cc-devel
cd /tmp
cvs -d:pserver:anonymous@lcd4linux.cvs.sourceforge.net:/cvsroot/lcd4linux login <--just hit return when prompted for a password
cvs -z9 -d:pserver:anonymous@lcd4linux.cvs.sourceforge.net:/cvsroot/lcd4linux co lcd4linux
cd lcd4linux
./configure
make
make install

That's it for installing LCD4Linux software. That was the easy part, the tricky part is the configuration file . I have modified the "lcd4linux.conf" file for use with the 411 Tech Systems LCD module to get you started. This config file should work for other "generic HD44780" modules as well.

cd /etc/
wget http://prestonmoore.com/images/lcd4linux.conf
chmod 600 lcd4linux.conf

Now you are ready testing. Cross your fingers and issue the following command:

lcd4linux -Fvv

With luck you should see the "default" layout displayed on your LCD. If you don't, you have some troubleshooting to do. I would first check the bios settings concerning the parallel port. I am using the "AT" setting versus the "ps/2" setting on my Dell Optiplex computers. If you are given the bios choice of EPP, ECP, or SPP then select SPP(Standard Parallel Port). If you are still having problems post them in the forum or check around for a solution.

You got it working and now you want LCD4Linux to run in the background. Issue the following:

lcd4linux (shows splash screen)
lcd4linux -q (suppresses splash screen)

Add this to the bottom of your /etc/rc.local file to make display start on boot:

echo "Starting LCD4Linux..."
/usr/local/bin/lcd4linux -q


LCD4Linux uses "widgets" to display various functions. You can make your own such as this one I made to display used memory:

Widget RAMused {
class 'Text'
expression (meminfo('MemTotal')-meminfo('MemFree'))/1024
prefix 'RAM '
postfix ''
width 8
precision 0
align 'R'
update tick
}

I guess you are getting the hang of it now. Good luck!

Anyone else with some interesting widgets please add to comments