On this page ...
Have you ever seen one of those sites,.. talking
about an MP3-player in your car or as a part of your standard stereo
set at home? Or an LCD display in you PC that indicates temperature
and CPU load?
Well, I have, and I definitly wanted to make one
myself. This first main point is that this is just an experiment,
so costs should be at a minimum.
First: Read the disclaimer!
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The LCD display itself
I started working on an LCD-panel-display, ... I found
a broken desktopmodel phone (model Ericsson DBC661) with a very nice 20x4
display based on a Hitachi 44780 controller.
Since the information on this display was pretty hard
to find, it took me a while to get it working. I used information of Seiko,
Optrex, Hitachi, some examples on the web from
Thanks to these people !!
I also have to specially thank Seiko Instruments
Germany for their excellent help and support !!
Interfacing this display proved to be easy in DOS, however
interaction between display-software and MP3-player was simply to hard...
so a friend of mine (Saber Karmous) suggested using Linux.
I have experience with Linux from my university-days,
so I decided to give it a try.
At first I tested the device-drive of Nils Faerber and
Michael Engel, which did not work for the way I interfaced the CPU and
the LCD. So I decided (with some help of Randy Rasa's DOS C-code) the
rewrite the device driver, which worked pretty well to.
Note: in the meanwhile a lot of tools support controlling
an LCD panel in your PC, like WinAmp
and MBM Monitor.
Wiring the display
This is the backside (componentside) of the display
found in the Ericsson DBC661. On the right-bottom side you'll see 14 pins.
Take a look at this PDF
file for how to wire this. Below you will find a little table showing
how to make the connections
1
|
Aarde |
25
|
2
|
+5 Volt |
17
|
3
|
Vee (LCD contrast) |
25
|
4
|
RS (Register Select) |
16
|
5
|
R/W (Read/Write) |
14
|
6
|
E (Edge Enable) |
1
|
7
|
DB0 (databit 0) |
2
|
8
|
DB1 (databit 1) |
3
|
9
|
DB2 (databit 2) |
4
|
10
|
DB3 (databit 3) |
5
|
11
|
DB4 (databit 4) |
6
|
12
|
DB5 (databit 5) |
7
|
13
|
DB6 (databit 6) |
8
|
14
|
DB7 (databit 7) |
9
|
It works !
After wiring the LCD to the parallelport I used Randy's
program to test the display in DOS,..
and it finally worked!
So it finally worked using a little piece of software
I wrote using Borland's Turbo Pascal for DOS (You
can download it here)... and after a while I got it working with Linux
aswell (download the device driver
and a test application here). The fun part is that Linux is a faster
OS than DOS, finally I got an MP3 application running aswell on an old
Pentium 75 Mhx machine (and those puppy's are reeealllllyyyyy slow)...
In the LCDLinux.zip you'll find
"lcd.tar" with Linux sources. The application-source
"lcdtest.c" demonstrates how one can use the display
without an device driver. Checkout the README for more software info.
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