Quote Originally Posted by santamaria View Post
I am using pic 16f628 with pic basic pro compiler ver 2.46.I am tying to display to an lcd screen equivalent to hd44780 the word hello but i can't make it.When i use the same program with 4bit interface everything working fine(DEFINE LCD_BITS 4).but when i choose 8 bit nothing appear to lcd.I don't know also if the connection is correct because i never used before 8bit interface.the 4bit connection is according to manual.
Which LCD module are you using? There are a few modules out there that only operate in the 4 bit mode, but still have what looks like an 8 bit connector.

Don't need 'DEFINE LCD_DBIT 0' when using 8 bit mode, don't know if it makes a difference or not.

Try increasing 'commandus' (word value) and 'dataus' (byte value) and see what happens. Generally, 'commandus' has always worked for me at a max value of 2500, and 'dataus' had to be set to a max value of 100 for one setup.