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hd44780 4x20 problem
http://forum.lcdinfo.com/viewtopic.php?f=6&t=504		 Page 1 of 1
Author:  TCPMeta [ Sat Jan 31, 2004 3:23 ]
Post subject:  hd44780 4x20 problem
Ok, I just got a HD44780 4x20 LCD. I used the pinout from http://www.mikrocontroller.net/lcd.en.htm and installed port95 oh and Smartie. Anyway when I startup Smartie the LCD blinks twice of two lines (the 2nd and 4th lines) and then nothing else after that. I checked and rechecked my wireing and its all fine. I even tryed rewireing it to be on the safe side. I've also tryed every setting for my LPT port in the BIOS and nothing seems to work. Can anyone tell me of a diffrent I/O driver or LCD program to use?

Oh and i'm running Windows ME if that helps.

-TCPMeta
Author:  rudi Grobler [ Mon Feb 02, 2004 8:20 ]
Post subject: 
Hi,

LCDInfo supports a HD44780 driver (It is still in development) but it might help. Have a look at the following thread:

http://www.skippari.net/phpBB2/viewtopic.php?t=382

Hope it helps...
Author:  Ward [ Wed Feb 11, 2004 4:58 ]
Post subject: 
I have the exact same problem as you, and its frustrating me to death at the moment. I have rewired several times, and at the moment I am even using a 'breadboard' just so I dont have to keep soldering and desoldering stuff :P I have the 1st and 3rd lines all black, backlight and contrast work perfectly. I wired mine using this article:

http://www.myrolypoly.com/lcd_project/lcd_project.html

I have tried several other hd44780 displays, including another 4x20, as well as 3 1x16, and I get the same thing with all of them - only the initialization screen. I have also tried this with 3 different computers, 2 of which are Windows XP pro, and my laptop which runs Windows 98 SE. The only thing I can possibly think of now is that the LCD is simply not getting data from the computer. I am using a ribbon cable, about 2' in length to connect the LCD to the serial port. I am thinking that its either picking up interference, or just isnt carrying a strong enough signal. I am about to rewire yet again, using a quality parallel cable with EMI and RF filters on it. Any suggestions?
Author:  Ward [ Wed Feb 11, 2004 5:28 ]
Post subject: 
Still doesnt work. WTF???? I am pulling my hair out trying to get this to work...

EDIT: I think I figured it out. I swear if this is all it is then I am gonna smack myself...

Yep, I figured it out. I was looking at the parallel pinout backwards. When I soldered the ribbon cable to the DB25 connector, I didnt realize I was looking at the back of the DB25 connector, therefore mirroring the pins. But It finally freakin works!
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