• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

LCD Newbie needs help!


New member
I have this cool project in process that involves hooking a C.F.
16x2 Character LCD to my parallel port. I have hooked it up and I get the "boxes" on the LCD to light up upon powerup.
The problem is that the lit up boxes don't go away.
I can see the display is recieving what I am sending it, but ever so faintly as the boxes dominate the screen. Its almost as if the "test pattern" is staying on, not allowing the message to have the nice contrast that it should have, making it nearly unreadable. Any suggestions?
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.


New member
3rd pin grounded

I read the 3rd pin being grounded is suppose to give greatest contrast. I have mine grounded, do I need to adjust voltage to this pin to try different contrasts? I will verify tonight that the ground is good. Any other tips on contrast would be great,


New member
Snoopin around

Well the more snoopin around I am doing the more it looks like I need to wire up a 10K pot. to the contrast line. If any of you out there with morew LCD experience think I'm on the right/wrong track let me know.


New member
did you get this resolved?

I'm having a similar problem. Did you ever get your problem figured out? Did you ground the 3rd pin or give it a certain voltage?