44780 LCD queries

[ankur]

Hi everyone,
I am trying to use CCM1620CSL(a 44780-based LCD module) and that is
the first LCD i am trying my hands on.
I have interfaced the LCD to a PIC and till now, whatever program I
run, the result is 16 black boxes on the 2nd line of LCD (it's a 16x2
LCD). Can anyone suggest why is it happening? Isn't the LCD
auto-initialized in the 8-bit, 1-line mode when no initialization
routine is found ?

I've few more questions:
1) Can initialization be done only at the time of applying power to
the LCD? Suppose I wish to change the entry mode in the middle of my
program, how is it done?

2) Ideally, what do you expect to see on the LCD screen if ONLY power
is applied(i.e only Vdd,Vss & Vo are connected and rest of the pins are
left open)

Any help is welcome.
TIA
-Ankur

 

[ankur]

Hello Webb,
Thank you for the elaborate suggestions. The data sheet I currently
have, is least informative and I couldn't find any other datasheet of
the same manufacturer on the web.

I will work more on getting the initialization right. Can you tellme
what is observed on the screen when it gets initialized
successfully?(incase it is not different for different modules)

And the black bar(16 consequtive boxes) are in the lower line(line
TWO, i guess). And I don't think that the display might be reversed
internally.Still, I'll find it out once i get through something.

Thanks & Regards
-Ankur

 

This page tells you how to initlize the 44780.
Check out the links given on this page as well. My first success was a
result of reading this page. I would forget the data-sheets, except
for pin hookups, and timing requirements. Those things still confuse
me sometimes.


http://www.myke.com/lcd.htm