LCD troubles.... (BASIC STAMP 1)

Archiver · 2002-01-06 15:56

Hello,

I'm running into an odd problem with the BASIC
Stamp 1 and an OPTREX DMC 16128 LCD module (16x1).
The Stamp 1 drives one of my other 16x1 displays
ok but when I connect it to the OPTREX 16128 LCD
it will only display the first 8 characters. I've
got a few of these modules and they all do the
same thing. I'm at a loss as to why I can't get
the last 8 characters to display. If possible I
would like to get them to work since they are nice
large character displays.

Thanks,

Robert

Archiver · 2002-01-06 16:01

Some displays treat the 16 x 1 displays as a 2 x 8 -- ie you have to do a
line feed or count over a certain number of characters to get to the 2nd 8
characters on the display. This sounds like the cheesy displays I got with
my serial interface boards from MPJA.

As a side note, I finally did get the MPJA serial boards working -- but you
may have to turn the robot off / on 3-4 times to get the display to
initialize properly.

Original Message

> I'm running into an odd problem with the BASIC
> Stamp 1 and an OPTREX DMC 16128 LCD module (16x1).
> The Stamp 1 drives one of my other 16x1 displays
> ok but when I connect it to the OPTREX 16128 LCD
> it will only display the first 8 characters. I've
> got a few of these modules and they all do the
> same thing. I'm at a loss as to why I can't get
> the last 8 characters to display. If possible I
> would like to get them to work since they are nice
> large character displays.
>
> Thanks,
>
> Robert
>
>
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Archiver · 2002-01-07 13:08

I did some more testing and you must be right about my display. I
plugged it into a HandyBoard and the first line was shown in the
first 8 characters and the second line was shown in the last 8
characters.

I tried sending a linefeed (and later a CR) but still could not
write to the second bank of 8 characters on the display with the
Stamp 1. I am using the example program SERVO.BAS with the display.
I am beginning to wonder about the way it initializes the LCD and if
it might be setting it for 1 line operation. If that is the case
then I wouldn't be able to use the rest of the display since it would
be on the second line.

Anyone else see this problem before? Maybe there is a better way
to init the display.

Robert

--- In basicstamps@y..., Rodent <daweasel@s...> wrote:
> Some displays treat the 16 x 1 displays as a 2 x 8 -- ie you have
> to do a line feed or count over a certain number of characters to
> get to the 2nd 8 characters on the display. This sounds like the
> cheesy displays I got with my serial interface boards from MPJA.
>
>

Original Message

>
> > I'm running into an odd problem with the BASIC
> > Stamp 1 and an OPTREX DMC 16128 LCD module (16x1).
> > The Stamp 1 drives one of my other 16x1 displays
> > ok but when I connect it to the OPTREX 16128 LCD
> > it will only display the first 8 characters. I've
> > got a few of these modules and they all do the
> > same thing. I'm at a loss as to why I can't get
> > the last 8 characters to display. If possible I
> > would like to get them to work since they are nice
> > large character displays.

Archiver · 2002-01-07 14:37

What you need to do is change the DDRAM address to the first character of the
second line. GOTO this link:

http://members.aol.com/jonwms/stamps

and download the file LCDDEMO2.BAS. It will show you how to deal with at
two-line display using the BS1.

-- Jon Williams

In a message dated 1/7/02 7:09:43 AM Central Standard Time,
rdoerr@b... writes:

> I did some more testing and you must be right about my display. I
> plugged it into a HandyBoard and the first line was shown in the
> first 8 characters and the second line was shown in the last 8
> characters.
>
> I tried sending a linefeed (and later a CR) but still could not
> write to the second bank of 8 characters on the display with the
> Stamp 1. I am using the example program SERVO.BAS with the display.
> I am beginning to wonder about the way it initializes the LCD and if
> it might be setting it for 1 line operation. If that is the case
> then I wouldn't be able to use the rest of the display since it would
> be on the second line.
>
> Anyone else see this problem before? Maybe there is a better way
> to init the display.
>

[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver · 2002-01-07 22:27

I believe you do have to send a command to the LCD chipset telling it that
its two lines. You might also try sending characters 8 at a time, like
11111111 22222222 33333333 -- the 1's should show up in the first 8
characters, and whatever shows up in the last 8 will tell you how many
characters per line it expects.

Here are two sites for LCD's based on Hitachi chipsets:

http://home.iae.nl/users/pouweha/lcd/lcd.shtml

http://www.ferrara.linux.it/members/munehiro/lcd/hd44780_lcd0.htm

Original Message

> I did some more testing and you must be right about my display. I
> plugged it into a HandyBoard and the first line was shown in the
> first 8 characters and the second line was shown in the last 8
> characters.
>
> I tried sending a linefeed (and later a CR) but still could not
> write to the second bank of 8 characters on the display with the
> Stamp 1. I am using the example program SERVO.BAS with the display.
> I am beginning to wonder about the way it initializes the LCD and if
> it might be setting it for 1 line operation. If that is the case
> then I wouldn't be able to use the rest of the display since it would
> be on the second line.
>
> Anyone else see this problem before? Maybe there is a better way
> to init the display.

LCD troubles.... (BASIC STAMP 1)

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