AVR-Chat

----Original Message----
From: AVR-Chat@yahoogroups.com
[mailto:AVR-Chat@yahoogroups.com] On Behalf Of Dave
McLaughlin Sent: 03 October 2009 17:50 To:
AVR-Chat@yahoogroups.com Subject: RE: [AVR-Chat] ATMega16 +
WH1602 

> Is the second line OK?
> 
> Have you adjusted the contrast input to the device? If
> this voltage is 
> wrong, the display will show as solid boxes. Another
> reason could be the 
> RESET is not working.
> 

Top line filled with black boxes means that the LCD module is not
initialised.
If it was contrast, both lines would be black (or blank).

Can you wiggle a pin to check if your code is actually running?

If code is running then I would guess it is a timing problem in the LCD
setup routines. The timings can be a bit unpredictable between different
displays.

-- 
Tim Mitchell