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Topic: lcd tutorial not work on 4x20 :-( (Read 827 times) previous topic - next topic

emaaaa

hi, i'm new to arduino.
I try to use a 4x20 hd4470 based lcd with arduino's lcd tutorial but it don't work
Display show #1 and #3 lines with all characters black and #2 and #4 lines empty characters.

some idea?

i''ve tried 8-bit tutorial and 4-bit tutorial, without solutions :-(

thx!

MikMo

Some 4x20  displays have 2 hd4470 IC's to control them, maybe that is your problem ?

tr909

Not sure where but there is mod to the library to work with 4 lines. I'm still waiting for my 4 line to arrive.

This may be it:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1170601618


Cheater

I have the same problem.

Its not really a problem by its self actually.
It just means that your not talking to it correctly (its the default state). Once you have it working properly then the bars will go away and the extra lines will work perfectly.

No dont ask me why its not working. I dont have a clue.
If I did I'd have my LCD working and I'd be a happy man. ;)

emaaaa

Hi, sorry for my long time response, in italy there's holiday :-)

So...
I've tried to use this tutorial:
http://www.arduino.cc/en/Tutorial/LCD8Bits
without using library.

It's works!
lcd library using 8bits maybe dosen't talk correct to lcd.

i will debug LCD libray code, download on site, ASAP!

stay tuned.

thx for replays!

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