Mike Keitz wrote:

> There are 2 types of 16x1 modules out there.  One type has the HD44780
>
> chip and an LCD driver chip.  It uses x8 or x11 drive for a true
> 16-character by one line.  The characters appear sequentially in RAM.

> The other type has only the HD44780 chip.  The controller must be set
> for
> x16 drive, since it is logically an 8x2 display.  The LCD panel is
> built
> so the 2 lines appear end to end rather than above each other.  There
> is
> a gap in the RAM between the two sides of the display just like the
> gap
> in RAM between the two lines of a 2-line display.
>
> If you're only seeing the left 8 characters on the display it is
> likely
> the x16 type.  There is no way to test with software what kind it is.
>

What I get when power it up and adjust the contrast, is 8 dark blocks
left, and 8 lighter ones to the right.

When I run Niki's program all 16 character become lighter - so I assume
it is initialised.
At this point, I can't get it to display anything else. I'll ask Niki,
since I had to change one or two things to get MPASM to assemble it.

Is it possible to destroy just the data display part of the LCD. I find
it unlikely that soldering my pins on it could destroy the bugger.

> Even without any commands from the PIC, the HD44780 will reset itself
> into x8 mode and clear the display RAM at power-on.  So when the power
> is
> turned on and the LCD drive voltage sufficiently high (or low, since
> it
> is relative to Vdd), some or all of the characters should change to
> dim
> or dark blocks.  THis is a pretty good test of the LCD module.

OK mine does that (allready mentioned)

> If you
> can't get anything at all on the screen you may have one of the
> high-temperature modules which requires more than 5V of LCD drive.  In
>
> that case the LCD drive pin needs to be pulled negative a few volts.

But that would guarantee that a normal temp one would loose its
smoke....

Cheers! And thanks for the help!

--
Eric van Es               | Cape Town, South Africa
mailto:vanes@ilink.nis.za | http://www.nis.za/~vanes
LOOKING FOR TEMPORARY / HOLIDAY ACCOMODATION?
http://www.nis.za/~vanes/accom.htm