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Re: [AVR-Chat] Help debugging LCD display issues

Re: [AVR-Chat] Help debugging LCD display issues

2005-12-05 by MuRaT KaRaDeNiZ

Hi,
in 4bit mode where should we connect the unused bits?
Show quoted textHide quoted text
-----Original Message-----
    From: "James Washer" <washer@trlp.com>
    Sent: 27.11.05 01:11:36
    To: "AVR-Chat@yahoogroups.com" <AVR-Chat@yahoogroups.com>
    Subject: Re: [AVR-Chat] Help debugging LCD display issues
    
    Nice tip... thanks... as it turns out.. I think the problem was that I'd left D[0..3] floating on the LCD
    
    
    
    On Sat, 26 Nov 2005 09:58:37 -0800 (PST)
    amol_deshmukh <aad_iit@yahoo.com> wrote:
    
    > hi
    >   i was stuck up with LCD for about half a month for a very small reason. i too had done everything correctly. 
    >   i was trying to use LCD with AtMega16 in 4 bit mode using Port C. the  JTAG bit on Port C wasnt diabled and for this tiny thing could not get  LCD running. u might wanna check into that.
    >   
    >   -- 
    >   Amol Deshmukh
    >   3rd Yr. Undergraduate
    >   Dept. of Mechanical Engg.
    >   IIT - Bombay, India
    >   
    >   
    > Message: 1         
    >    Date: Fri, 25 Nov 2005 13:50:35 -0800
    >    From: James Washer 
    > Subject: Help debugging LCD display issues
    > 
    > I'm using an Optrex DMC16207 (HD44780) LCD display with a Mega32 and Peter Fleury's LCD library.
    > 
    > Using  the include test file, upon power-up, the top row of the display shows  all 16 cells "lit" (darkened) with EVERY bit position darkened (i.e. a  rectangle). The bottom row is blank.
    > 
    > I've checked and checked that all is hooked up well, but nothing changes... any ideas?
    > 
    > thanks
    > 
    >  - jim
    > 
    > 
    > ________________________________________________________________________
    > ________________________________________________________________________
    > 
    > Message: 2         
    >    Date: Fri, 25 Nov 2005 20:52:52 -0600
    >    From: David Kelly 
    > Subject: Re: Help debugging LCD display issues
    > 
    > 
    > On Nov 25, 2005, at 3:50 PM, James Washer wrote:
    > 
    > > I'm using an Optrex DMC16207 (HD44780) LCD display with a Mega32  
    > > and Peter Fleury's LCD library.
    > >
    > > Using the include test file, upon power-up, the top row of the  
    > > display shows all 16 cells "lit" (darkened) with EVERY bit position  
    > > darkened (i.e. a rectangle). The bottom row is blank.
    > 
    > Thats what an HD44780 looks like when its uninitialized.
    > 
    > My guess is that you are not talking to it at all.
    > 
    > --
    > David Kelly N4HHE, dkelly@HiWAAY.net
    > ========================================================================
    > Whom computers would destroy, they must first drive mad.
    > 
    > 
    > 
    > ________________________________________________________________________
    > ________________________________________________________________________
    > 
    > Message: 3         
    >    Date: Fri, 25 Nov 2005 20:51:57 -0800
    >    From: James Washer 
    > Subject: Re: Help debugging LCD display issues
    > 
    > Yes, I'm beginning to think that is the case. Thanks
    > 
    >  - jim
    > 
    > On Fri, 25 Nov 2005 20:52:52 -0600
    > David Kelly  wrote:
    > 
    > > 
    > > On Nov 25, 2005, at 3:50 PM, James Washer wrote:
    > > 
    > > > I'm using an Optrex DMC16207 (HD44780) LCD display with a Mega32  
    > > > and Peter Fleury's LCD library.
    > > >
    > > > Using the include test file, upon power-up, the top row of the  
    > > > display shows all 16 cells "lit" (darkened) with EVERY bit position  
    > > > darkened (i.e. a rectangle). The bottom row is blank.
    > > 
    > > Thats what an HD44780 looks like when its uninitialized.
    > > 
    > > My guess is that you are not talking to it at all.
    > > 
    > > --
    > > David Kelly N4HHE, dkelly@HiWAAY.net
    > > ========================================================================
    > > Whom computers would destroy, they must first drive mad.
    > > 
    > 
    >   
    > 
    > 
    > 
    > amol deshmukh
    > mechanical engg.
    > IIT-B, Powai ,Mumbai
    > 		
    > ---------------------------------
    >  Yahoo! Music Unlimited - Access over 1 million songs. Try it free.
    
    
    
     
    Yahoo! Groups Links

Re: [AVR-Chat] Help debugging LCD display issues

2005-12-05 by James Washer

I tied them to ground using 2.2Kohm... but that was just what I had on the bench at the time. I don't think it's all that critical..

 - jim
On Tue, 6 Dec 2005 00:25:21 +0200
"MuRaT KaRaDeNiZ" <karademu.yahoogroups@onlinefavbar.com> wrote:
Show quoted textHide quoted text
> Hi,
> in 4bit mode where should we connect the unused bits?
> 
> -----Original Message-----
>     From: "James Washer" <washer@trlp.com>
>     Sent: 27.11.05 01:11:36
>     To: "AVR-Chat@yahoogroups.com" <AVR-Chat@yahoogroups.com>
>     Subject: Re: [AVR-Chat] Help debugging LCD display issues
>     
>     Nice tip... thanks... as it turns out.. I think the problem was that I'd left D[0..3] floating on the LCD
>     
>     
>     
>     On Sat, 26 Nov 2005 09:58:37 -0800 (PST)
>     amol_deshmukh <aad_iit@yahoo.com> wrote:
>     
>     > hi
>     >   i was stuck up with LCD for about half a month for a very small reason. i too had done everything correctly. 
>     >   i was trying to use LCD with AtMega16 in 4 bit mode using Port C. the  JTAG bit on Port C wasnt diabled and for this tiny thing could not get  LCD running. u might wanna check into that.
>     >   
>     >   -- 
>     >   Amol Deshmukh
>     >   3rd Yr. Undergraduate
>     >   Dept. of Mechanical Engg.
>     >   IIT - Bombay, India
>     >   
>     >   
>     > Message: 1         
>     >    Date: Fri, 25 Nov 2005 13:50:35 -0800
>     >    From: James Washer 
>     > Subject: Help debugging LCD display issues
>     > 
>     > I'm using an Optrex DMC16207 (HD44780) LCD display with a Mega32 and Peter Fleury's LCD library.
>     > 
>     > Using  the include test file, upon power-up, the top row of the display shows  all 16 cells "lit" (darkened) with EVERY bit position darkened (i.e. a  rectangle). The bottom row is blank.
>     > 
>     > I've checked and checked that all is hooked up well, but nothing changes... any ideas?
>     > 
>     > thanks
>     > 
>     >  - jim
>     > 
>     > 
>     > ________________________________________________________________________
>     > ________________________________________________________________________
>     > 
>     > Message: 2         
>     >    Date: Fri, 25 Nov 2005 20:52:52 -0600
>     >    From: David Kelly 
>     > Subject: Re: Help debugging LCD display issues
>     > 
>     > 
>     > On Nov 25, 2005, at 3:50 PM, James Washer wrote:
>     > 
>     > > I'm using an Optrex DMC16207 (HD44780) LCD display with a Mega32  
>     > > and Peter Fleury's LCD library.
>     > >
>     > > Using the include test file, upon power-up, the top row of the  
>     > > display shows all 16 cells "lit" (darkened) with EVERY bit position  
>     > > darkened (i.e. a rectangle). The bottom row is blank.
>     > 
>     > Thats what an HD44780 looks like when its uninitialized.
>     > 
>     > My guess is that you are not talking to it at all.
>     > 
>     > --
>     > David Kelly N4HHE, dkelly@HiWAAY.net
>     > ========================================================================
>     > Whom computers would destroy, they must first drive mad.
>     > 
>     > 
>     > 
>     > ________________________________________________________________________
>     > ________________________________________________________________________
>     > 
>     > Message: 3         
>     >    Date: Fri, 25 Nov 2005 20:51:57 -0800
>     >    From: James Washer 
>     > Subject: Re: Help debugging LCD display issues
>     > 
>     > Yes, I'm beginning to think that is the case. Thanks
>     > 
>     >  - jim
>     > 
>     > On Fri, 25 Nov 2005 20:52:52 -0600
>     > David Kelly  wrote:
>     > 
>     > > 
>     > > On Nov 25, 2005, at 3:50 PM, James Washer wrote:
>     > > 
>     > > > I'm using an Optrex DMC16207 (HD44780) LCD display with a Mega32  
>     > > > and Peter Fleury's LCD library.
>     > > >
>     > > > Using the include test file, upon power-up, the top row of the  
>     > > > display shows all 16 cells "lit" (darkened) with EVERY bit position  
>     > > > darkened (i.e. a rectangle). The bottom row is blank.
>     > > 
>     > > Thats what an HD44780 looks like when its uninitialized.
>     > > 
>     > > My guess is that you are not talking to it at all.
>     > > 
>     > > --
>     > > David Kelly N4HHE, dkelly@HiWAAY.net
>     > > ========================================================================
>     > > Whom computers would destroy, they must first drive mad.
>     > > 
>     > 
>     >   
>     > 
>     > 
>     > 
>     > amol deshmukh
>     > mechanical engg.
>     > IIT-B, Powai ,Mumbai
>     > 		
>     > ---------------------------------
>     >  Yahoo! Music Unlimited - Access over 1 million songs. Try it free.
>     
>     
>     
>      
>     Yahoo! Groups Links
>     
>     
>     
>      
>     
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
>

Re: [AVR-Chat] Help debugging LCD display issues

2005-12-06 by John Samperi

At 09:49 AM 6/12/2005, you wrote:

>I tied them to ground using 2.2Kohm..

No need to do anything, the displays have built in pull up
resistors. At least I have never had to do anything and
haven't had any problems with the brands I have used :-)


Regards

John Samperi

********************************************************
Ampertronics Pty. Ltd.
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Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
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