LCD Woes

Hello all! I've been reading this forum, and all the docs on the wiki, etc, while waiting on my deicimila to arrive. So, it's all here, and I've done lots of little circuits playing with I/O, etc.

So, I decided to take the plunge and hook up an LCD (GDM1602K from Sparkfun), followed the docs on in the lcd tutorial, and did everything there (including, according to a search here, re-defining the arguments to a few functions in LiquidCrystal.cpp). However, I'm quickly banging my head against the wall.

I can't seem to get it working, and am running low on things I can do to figure out what I've done wrong.

I've wired and re-wired a dozen times to make sure I'm not making a mistake there, and I know I've done it according to the tutorial.

I see a flow of ~ 5V going into DB0 (pin #7 on LCD) when I run the "abc" demo. There's no current into DB0 when I comment out the code that writes data to the lcd.
The backlight works fine.
I get a good 5.06V going through the power of the LCD.

But nothing is displayed?

The only thing odd I can find is that there is always 5.06V going through the contrast adjustment pin (#3 on the LCD), but I've checked my (10K) pot, and it's sending 4.06V to that pin on the LCD.

Are there any things I can try to isolate whether the LCD is broken (say, a simple circuit that should display some gobble-de-gook?) or that there's something else going on in the LCD code on the Arduino? Unfortunately, I have some experience with circuit building (mostly 555 timers and some simple synth-type work), but just enough of it to have found myself up a creek without a solution =)

Thanks in advance!

!c

Check the contrast wiring. One lead of the pot should go to +5v, the other to gnd, with the middle lead being the contrast out to the LCD. When you adjust the pot then voltage on the the pin of the LCD should vary. the LCD should display a bunch of dark blocks when adjusted one way and nothing when adjusted the other. Proper adjustment when be just before the dark blocks appear.

Check the contrast wiring. One lead of the pot should go to +5v, the other to gnd, with the middle lead being the contrast out to the LCD. When you adjust the pot then voltage on the the pin of the LCD should vary. the LCD should display a bunch of dark blocks when adjusted one way and nothing when adjusted the other. Proper adjustment when be just before the dark blocks appear.

Ack. Now I feel kinda dumb - I had tried a bunch of different things, but somewhere in the process, the jumper wire to the side of the breadboard between contrast pin and where I had hooked up the pot had the tip break off. Thanks for pointing me back there, if I hadn't skipped over that side of the board and just plugged in next to the LCD its self, I would've never noticed!

Now it works =)

!c