Chaipi Wijnbergen wrote:

> I have two types of LCD modules, each is 14 pin, 2 lines of 16
> characters.
> It looks like one type has VCC, GND in pins 1 & 2.
> And the other type has VCC, GND in pins 13 & 14.
> What is the difference between those two modules? are they software
> compatible?

  It's ridiculously obvious, but perfectly true, that in the case of the
second unit, someone has numbered it in reverse.  Whether by malicious
intent or mere foolishness is hard to figure.

  Just make sure you know which is ground (on most PCBs, ground is the
largest area of copper) and which Vcc, check that the "contrast"
connection goes to the resistor chain, and all the other connections
(which won't be damaged anyway if mis-wired as they are all in effect,
inputs most of the time) will presumably follow the pattern.

  If you don't have the datasheet reference, we can find it.  Of course,
Hitachi went and *moved* it a while back, demonstrating the "modern"
preference for form over functionality, but .... that's life!
--
  Cheers,
        Paul B.