Hello,
I picked up an LCD but can't get it working. I think I've got the pins set up wrong.
I'm using the 'hello world' example on my arduino duemilanove, and I have a DEM16217, datasheet here: http://www.soselectronic.com/a_info/resource/d/dem/dem16217syh-py.pdf
Can anyone help me out, please?
So how have you got it wired up? What are you doing with pin 3. What do you see? Have you got a resistor in line with the back light LED?
I've got it wired as according to this: http://oomlout.com/LCDD/LCDD-Guide.pdf except the bottom two cables (+5v and GND) are shifted appropriately. The 14 pins are otherwise the same, and I've got the potentiometer hooked up.
The backlight illuminates but that's all.
Try turning the contrast potentiometer all the way counter-clockwise and then
all the way clockwise. In one of those states you should see something
on the screen (usually black rectangles).
Did you make sure that the pin variables in the program match your wiring?
(* jcl *)
www: http://www.wiblocks.com
twitter: http://twitter.com/wiblocks
blog: http://luciani.org
I've tried turning the potentiometer, jcl, it didn't make anything visible.
Initially I wired it up wrong (exactly the same as on the oomlout.co.uk design) and I did see flashes of the black rectangles so I know it works. I have two identical screens, I've tried them both on the wiring that should be ok (so I don't think I broke the first with the bad wiring).
As far as I can tell the pins are right - but it's still not working so I thought I'd ask in here 
cowjam:
You could try Lady Ada's new tutorial at Arduino Tutorial - connecting a parallel LCD. If you can't get a good LCD working by following that tutorial then you need a new hobby/profession.
Don
Thanks Don, I'll give it a go.
The very simple step-by-step guide on lady ada helped - my potentiometer was at fault. All working now, thanks all.