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[lcdproc] Optrex DMC40457 4x40 LCD

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  • From: tse AT (Benjamin Tse)
  • Subject: [lcdproc] Optrex DMC40457 4x40 LCD
  • Date: Tue, 28 Mar 2000 10:22:01 +1000

On Mon, Mar 27, 2000 at 08:41:42AM -0700, EXT
gimp AT
> I subscribed to this mailing list yesterday, requested a bunch of ole
> emails, read them, and I think I'm more confused than when I started.
> I have an Optrex DMC40457 4x40 LCD. This is one of those LCDs that has
> two HD44780 chips on it, so it has two control lines and acts like 2 2x40
> screens. It has 16 pins on onw side (only 15 are used) and two power pins
> on the other (I'm not sure which is pos or ground).

This device should be supported by the server (but 4x40 isn't necessarily
supported by clients).

> I read that people were hooking their LCDs up to the printer port or the
> serial port. Is this right? How do I know which one to use, and where to
> I go to learn what pins on my LCD go to what pins on the port I need to
> use?

We've been using the parallel port. You'll need a few things to get started.

First info about the connections on your Optrex LCD:

Info about the connections to the parallel port (from sourceforge):

The relevant section is (you need to connect LCD 2 to the second
enable line of your LCD):

1.3 8-bit

This type of connection should work with winamp.

printer port LCD

D0 (2) D0 (7)
D1 (3) D1 (8)
D2 (4) D2 (9)
D3 (5) D3 (10)
D4 (6) D4 (11)
D5 (7) D5 (12)
D6 (8) D6 (13)
D7 (9) D7 (14)
nSTRB (1) EN (6)
nLF (14) nRW (5) (EN3 6 - LCD 3) (optional)
INIT (16) RS (4)
nSEL (17) EN2 (6 - LCD 2) (optional)

Finally, a build of lcdproc. Either get the files on sourceforge with the
tag PORTABLE_HD44780_DRIVER or try the binary/source at:

Once it's all connected, invoke the server as root with something like:
LCDd -t 40x4 -d HD44780 "-c 8bit -v 2,2"

> Has anyone tried this LCD? It was given to me by someone who had it given
> to them by someone that told them it would work with LCDproc :)

I personally haven't tried this particular LCD so tell us how it goes :-).


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