Hello everyone,

With your help, I successfully modified the code so it has both polling
function and time out timer.  Yes, I check the busy flag BEFORE I send the
data to the LCD to save time.  Here is the code (under CCS PIC C).

Thanks again!
Thomas
//---------------------------------------------------------------------
// send data to LCD
//---------------------------------------------------------------------
void lcd_send_byte( byte address, byte data )
{
        long LCDTimer;

        LCDTimer = 0;
        lcd.rs = 0;
        while (bit_test(lcd_read_byte(),7))
        {
                ++LCDTimer;
                if (LCDTimer == 0xffff)
                        break;
        }
        lcd.rs = address;
        delay_cycles(1);
        lcd.rw = 0;
        delay_cycles(1);
        lcd.enable = 0;
        lcd_send_nibble(data >> 4);
        lcd_send_nibble(data & 0xf);
}






>From: Jai Dhar <jdhar@ENGMAIL.UWATERLOO.CA>
>Reply-To: pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU>
>To: PICLIST@MITVMA.MIT.EDU
>Subject: Re: [PIC]: LCD routine Lockup
>Date: Sat, 15 Mar 2003 21:13:17 -0500
>
>If you need code, I have some written for an f877 and f628, although I
>don't
>poll the busy flag. I was just doing a one off with a particular LCD, so I
>didn't worry about future compatibility. Let me know if you want it.
>
>Quoting Thomas N <thomasn101@HOTMAIL.COM>:
>
> > Thank you everyone for your help. You all are very, very helpful!  I
>will
> > use the polling method to check for the busy flag and also implement the
> > time out period just in case the LCD doesn't response.  I am still
>testing
> > the code right now.  It doesn't work yet...
> >
> > Regards,
> > Thomas.
> >
> >
> > >From: samo benedihih <samo.benedicic@VOLJA.NET>
> > >Reply-To: pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU>
> > >To: PICLIST@MITVMA.MIT.EDU
> > >Subject: Re: [PIC]: LCD routine Lockup
> > >Date: Sat, 15 Mar 2003 23:35:59 +0100
> > >
> > >Hi!
> > >
> > >Check here: http://www.epemag.com/library.html. for tutorial on LCD's.
>It
> > >has all I needed to know about LCD's on just a few pages,  including
> > >tipical
> > >times for certain operations on LCD to complete. It also says that
>LCD's
> > >sometimes lock up when you poll busy flag. Regards, Samo
> > >
> > >
> > > > Hi everyone,
> > > >
> > > > My LCD routine checks the busy flag of the LCD and make sure the LCD
>is
> > >not
> > > > busy before writing new data to it.  Therefore, if there is
>something
> > >wrong
> > > > with the LCD module, my system hangs because it keeps checking and
> > >waiting
> > > > for the LCD to be ready.  Is there a way around this?  Thank you for
> > >your
> > > > help!
> > > >
> > > > Regards,
> > > > Thomas
> > > >
> > >
> > >--
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