Help with LCD Scroll

[ozarkshermit]

Howdy

I'm using a 4 x 20 LCD, and scrolling a text message from right to left. That is no problem. The letters "fall off" line one of the display as they reach the end of the first line, and then continue to scroll on line 3. What I want to do is, as the letters reach the end of line one, then restart over on line one, rather than "wrapping" and continuing on line 3. It would be OK if the entire message scrolls off before restarting.

I realize that this "line wrapping" is the way the display normally works., since there are 40 character positions per line, and line one actually continues starting on line 3. Also line 2 continues on line 4.

I thought the sending the command 68 would disable "line wrapping" , but that does not work.

I have searched every related thread I can find, but do not find this discussed. The HD44780 data sheet might explain how to do it, if possible, but I have not found that either.

Is there a way do do this?

Thanks

Ken

[andybarrett1]

HD44780.pdf

LCD Datasheet Enclosed.

[ozarkshermit]

Thanks Andy.
I guess I wasn't clear, I do have the data sheet, but have not found how to do this. If it is in there, it's not very clear (at least to me)

I have tried several different scrolling methods, some of which were in links that I found by searching the PBP forums.
Yes, they all do a nice scroll, but on a 4 x 20 LCD screen the text "wraps" from line one to line 3 , and after line three scrolls off, it "wraps back to line one. I only want to display the scroll on Line one.

Ken

[Tabsoft]

Ken,

Here is a link to a good thread lead by Melanie, long time PBP contributor, about this very subject.

Topic of the thread: "i just want to know how it is possible to scroll just 1 line of a 4x20 lcd using LCDout. example if i wanted to scroll just line 2"

Perhaps it will help you.

pblist.melabs.com/forum/messages/3064/3672.html

Good Luck

[Heckler]

Might want to take a look at this thread...
http://www.picbasic.co.uk/forum/showthread.php?t=13084
Although it is "rolling" not scrolling.

dwight

[Art]

If it’s character by character scrolling you feed each character into a FIFO buffer of 16 char length,
(or however long a line of the display is) rotate the byte buffer (should be a byte array)
so the last character is ditched. You print the FIFO buffer to the display for each frame.