I find that to be a programming error.  I had the similar problem,
sometimes it would work just fine, sometimes the background would be so
dark (like before init) it is hard to read the text.  I played with the
timings a bit and that solved the problem (although not completely).  It
is curious though, I never had this problem when using pure asm, I
recently swithched to C and the problems began.  I cannot get the lcd to
work with C commands, so I used assembly.

IMHO,

=D6mer YALHI
oyalhi@teksan.com.tr
http://www.teksan.com.tr
Tel : +90 212 613 22 00
Fax: +90 212 544 70 35


-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Peter L. Peres
Sent: Thursday, August 15, 2002 9:27 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [PIC]: LCD Contrast Variation


On Wed, 14 Aug 2002, Thomas N wrote:

>Hello Everyone,
>
>My LCD was working fine with 8-bit interface mode.  When I change it to

>4-bit interface mode, the LCD contrast changes randomly each time I run

>the program (I use ICD).  Sometimes, the display is clear with no dark=20
>background, but sometimes the background is very dark and it's very=20
>hard to read the text on the LCD.  Anyone know why it is intermittent=20
>like this?  There is no improvement between floating the 4 un-used pins

>and grounding them.  Please help!

What is connected to Vlc ?

Peter

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