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fowardbias
- 14th March 2006, 00:10
Thinking about picking up a Optrex 20x4 LCD display but held back to run this by the forum. The display uses a Novatek NT3881 internal driver which appears to be pin compatible with the HD44780, although several sites say the addressing is different? How do I find out what drivers are truely HD44780 compatable? Also will PBP support a 4 line display (that is a HD44780 or compatible)? I know we can DEFINE a 2 line display. Thanks JS.

picster
- 15th March 2006, 00:13
4 line display: yes - you have to write the defines anyway, you just change it to 4-line.

different addressing scheme: I wouldn't touch it! You can find the Hitachi based LCDs at lots of online surplus stores as well as on ebay - they generally will say that they use that chip.

-----------Picster----------

fowardbias
- 15th March 2006, 16:33
I compared the character map between the two drivers and they are the same for most of the major characters. (fonts, numbers and most of the common signs. Some do map differently. The timing seems to be the same. So if I call for a like character with LCDOUT everything should work. If it maps to a different character it can't be used and I must run in some ASM code with perhaps a PAUSEUS for timing to get the character I need. This probable can be done with some extra bit-banging. The Optrex LCD is appealing because of the white background and high contrast. I must ponder this more, don't need a full can of worms right now.JS