Serial LCD vs. Parallel (HD 44780) LCD

Archiver

I am trying to build a radio-controlled talking clock with the BS2. I
am trying to use the LCD to display time. What are the advantages and
disadvantages of using both? Which would be better? I am also hooking
up the BS2 to the receiver and voice chip as well. I know that serial
uses one I/O port of the BS2 and that the parallel requires at least
6. Also, www.seetron.com has a special deal on a serial LCD fro $39.
I heard that serial LCD are more expensive to purchase than parallel
LCDs such as HD 44780. Is this a fact or a myth?

Any helpful replies would be appreciated.

Thanks,
RP

P.S. What does OEM stand for?

Archiver

Hi

The term OEM stands for Original Equipment Manufacturer.

The serial LCD is much easier to use. Using the SEROUT command you
send data to the LCD directly. Of course the LCD still requires
initialization, the data sent to the LCD has to be placed where you
want it on the display. Using a serial display is almost as easy as
sending data to the screen using DEBUG.

The serial display taxes the Stamp less, the display does more of the
work.

The serial display is WAY more expensive than a parallel LCD alone.
The serial display sends data over one stamp pin.

The parallel display requires that the Stamp does all the work. The
parallel display to the stamp requires 6 stamp pins. Characters to be
displayed are typically stored in EEPROM, then read from EEPROM. Once
read they are assigned a variable. A subroutine sends this character
to the LCD. This subroutine converts the character to 2 4bit nibbles,
then sends the nibbles to the LCD to be displayed. A few other things
happen along the way.

Say the time was "12:32:06" or something like that. You could not
sent that string to the LCD easily using a parallel LCD. The data
would have to go one digit at a time to the display. That goes for
the colon as well. Accomplishing this task would require a bit of
code. It would also tie up the processor. Depending on your
application this may or may not be a problem.

Me, I hate spending money. I figure 50 bucks for the stamp is enough.
I have managed to accomplish all I have set out to do using surplus
(5 dollars or less) LCD displays. I would try to get the thing to
work using the parallel LCD display before I popped for the serial
display.

Of course if this is a "time is money" deal then the serial display
is the hands down winner.

Regards

Rich

--- In basicstamps@y..., rpshah79@h... wrote:
> I am trying to build a radio-controlled talking clock with the BS2.
I
> am trying to use the LCD to display time. What are the advantages
and
> disadvantages of using both? Which would be better? I am also
hooking
> up the BS2 to the receiver and voice chip as well. I know that
serial
> uses one I/O port of the BS2 and that the parallel requires at
least
> 6. Also, www.seetron.com has a special deal on a serial LCD fro
$39.
> I heard that serial LCD are more expensive to purchase than
parallel
> LCDs such as HD 44780. Is this a fact or a myth?
>
> Any helpful replies would be appreciated.
>
> Thanks,
> RP
>
> P.S. What does OEM stand for?

Archiver

Check out the Serial LCD Kit from Professor Anderson which lets you
talk to a parallel display using the serout command.

Only $9.95 (without the display) and the shipping is very
reasonable.

www.phanderson.com


--- In basicstamps@y..., rpshah79@h... wrote:
> I am trying to build a radio-controlled talking clock with the BS2.
I
> am trying to use the LCD to display time. What are the advantages
and
> disadvantages of using both? Which would be better? I am also
hooking
> up the BS2 to the receiver and voice chip as well. I know that
serial
> uses one I/O port of the BS2 and that the parallel requires at least
> 6. Also, www.seetron.com has a special deal on a serial LCD fro $39.
> I heard that serial LCD are more expensive to purchase than parallel
> LCDs such as HD 44780. Is this a fact or a myth?
>
> Any helpful replies would be appreciated.
>
> Thanks,
> RP
>
> P.S. What does OEM stand for?