A workaround might be to just use some special pointer at the start or 
end of the line to show the current item as selected.  For instance :

"==> Item 1                        <=="
"    Item 2                           "
"    Item 3                           "
"    Item 4                           "

I know... inversion would look cooler.

Lucas wrote:
> You can read from the DDRAM for that line, byte by byte, invert the it and
> write it back.
> Or you can go through the CGRAM, the character that you need a byte at a
> time, invert the byte and write it out to the DDRAM.
>
>
>
>
> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
> Peter Feucht
> Sent: July 19, 2009 5:43 AM
> To: Microcontroller discussion list - Public.
> Subject: [EE:] Inverted LCD display
>
> Hi, all,
>
> sitting here on Sunday writing some code snippets to test my LCD...
>
> It's a 4 line LCD matrix text display, 40 characters each line, type
> EAW404B-NLW from Electronic Assembly.
> Everything works so far, I can write characters.
>
> My application needs to show a list of items shown in 4 lines, the user can
> then choose one of them by moving a cursor.
> BUT: I need to indicate the selected item by *inverting* the line.
> I read the data sheet over and over but cannot find any hint how to invert
> the displayed information. And no chance to call the manufacturer for it's
> Sunday...
>
> Has anybody done this before?
>
> Any help greatly appreciated!
>
> Thanks and have a nice weekend.
>
> Peter 
>
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