Welcome to WeetHet!


Managed Web Hosting by Liquid Web

Your IP address:
3.239.91.5
     
 
Print this page
- use Landscape
Search the
WeetHet Pages
WeetHet is being updated! - Current articles will slowly move to www.tweaking4all.com
For excellent webhosting that is reliable and affordable, we highly recommend: LiquidWeb

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!

Hardware ...

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

  • David Tait (Hardware)

  • Nils Faerber and Michael Engel (Linux software)

  • Randy Rasa (DOS software and hardware)

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

LCD Display pin LCD Functionality PC Parallelpoort
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

 

The PCB from the telephone LCD display

It works !

After wiring the LCD to the parallelport I used Randy's program to test the display in DOS,..
and it finally worked!

Guess what,... it works !

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.

 


 

 


Klik hier om te wisselen naar nederlandstalige pagina's You are currently on the English pages.