By right it should not stray that far.... Is your chip
really a Hitachi HD44870 chip or a compatible one?

John

--- Tarun Grover <tarun.grover@gmail.com> wrote:

> I've recently completed a project involving an LCD
> using this same
> controller.  What I found is that with the 2 LCD's I
> was using for testing,
> this initialization routine did not work.  What I
> found DID work was when I
> left out
> the first 3 'write4(3)' instructions.  Now, this
> goes against
> everything I've read on the internet and from
> Hitachi's Datasheet.  I
> only found 1 instance where someone used a different
> initialization
> scheme and this seemed to work for me.
> 
> Was there anything wrong with what I was doing or do
> different LCD's behave
> differently (even though they use the same
> controller)?
> 
> Here is my initialization routine:
> 
> void lcd_init(void)
> {
> LCD_EN_DIR = 0;                     //Set EN and RS
> lines to output;
> LCD_RS_DIR = 0;
> 
> TRISBbits.TRISB0 = 0;             //Set data lines
> to output;
> TRISBbits.TRISB1 = 0;
> TRISBbits.TRISB2 = 0;
> TRISBbits.TRISB3 = 0;
> 
> LCD_EN = 0;
> LCD_RS = 0;                          //Write control
> bytes.
> delay(1300000);
> 
> PORTB = 0x0002;                   //Set 4 bit mode.
> LCD_STROBE();
> 
> lcd_write(0x28);                     //4 bit mode,
> 1/16 duty, 5x8 font.
> lcd_write(0x08);                     //Display off.
> lcd_write(0x0C);                    //Display on,
> cursor on.
> lcd_write(0x06);                    //Entry mode.
> }
> 
> Any insights?
> 
> -Tarun.
> 
> On 4/3/06, M. Adam Davis <stienman@gmail.com> wrote:
> >
> > What is your LCD init routine?  I've never
> experienced that problem
> > with the cheap LCDs I have used with this routine:
> >
> > write4 just writes 4 bits to the LCD interface,
> write8 writes 8 bits
> > in two cycles of 4 bits.  The rest should be
> pretty explanatory,
> > except for the ??? which I sure could be
> determined from the data
> > sheet in short order.
> >
> > void initlcd(void)
> > {
> >         delayms(20);    // Wait for LCD to power
> up ( >15ms )
> >         RS=0;           // Set RS low for
> instruction
> >         write4(3);      // Set interface to 8 bits
> >         delayms(5);     // Wait for LCD execute
> instruction ( >4.1ms )
> >         write4(3);      // Set interface to 8 bits
> >         delayms(1);     // Wait for LCD execute
> instruction ( >100us )
> >         write4(3);      // Set interface to 8 bits
> >         delayms(5);     // Wait for LCD execute
> instruction (At this point
> >                         // we could actually start
> using the busy flag)
> >         write4(2);      // Set the display to 4
> bit interface
> >         delayms(5);     // Wait for LCD execute
> instruction
> >         write8(0x28);   // Set the display to two
> line and ???
> >         delayms(5);     // Wait for LCD execute
> instruction
> >         write8(6);      // ???
> >         delayms(5);     // Wait for LCD execute
> instruction
> >         write8(1);      // Clear the LCD
> >         delayms(5);     // Wait for LCD execute
> instruction
> >         write8(0xf);    // ???
> >         delayms(5);     // Wait for LCD execute
> instruction
> >         return;
> > }
> >
> > -Adam
> >
> > On 4/3/06, kravnus wolf <kravnus@yahoo.com> wrote:
> > > I have written code for the LCD from bgmicro
> > >
> > >
> >
>
http://www.bgmicro.com/prodinfo.asp?sid=0968912037037037604814310&prodid=LCD1022&page=1&cri=lcd&stype=3
> > >
> > > I managed to get it started and printing
> characters on
> > > it. What grips me is that if I reset the PIC
> through
> > > MCLR quickly and numerous times the LCD just
> prints
> > > blank! It seems that the LCD cannot handle quick
> > > restart over and over again. I am left
> > > clueless........
> > >
> > > Thanks,
> > > John
> > >
> > >
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> 
> 
> --
> Tarun Grover
> Computer Engineering & Management V
> McMaster University, Hamilton, ON, Canada
> Chair, McMaster IEEE Student Branch Computer Chapter
> grovert@mcmaster.ca - tarun.grover@gmail.com
> tarun_grover@ieee.org - 905-518-2743
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> http://www.piclist.com PIC/SX FAQ & list archive
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> 


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