LCD module 8X2 stucks afther 8th char

Feb 10, 2007 2 Replies

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blisca 19 years ago

Hi.i'm still crying on LCD module now i 'm using a Powertip PC0802a based on a ks0076,(it should be compatible with hd44780 8X2 modules...but does it really means that i can swap them without any difference?????)i wrote my routines in assembly language for a pic 16f628,4 bit interface

it works fine except the fact that i f write in the 8th column of a row it stucks

example

movlw '1' call send_data movlw '2' call send_data ... ... ... movlw '7' call send_data

call Delay ;time to show it

goon

it is ok,but if if i add a

movlw '8' call send_data

well,no way to move out from here

Any hints?

Thank you Diego Italy

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J.A. Legris 19 years ago

If the 8th character is on the 2nd line, then its address will continue from 0x40, not 0x08. I believe this is because, many years ago, the controller IC was designed to work with various sizes of LCD and the 64-character line (0x40) was chosen as the maximum length.

-- Joe Legris

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blisca 19 years ago

compatible

thank you,but the reason was prior to this...once again it is my fault............ drivin the lcd with 4 bits interface i did a mistake in the way i checked the busy flag...

the flag must be checked only on the first nibble....and if the check fails both nibbles must be sent again...it is evident by the timing diagram ,but i interpreted it wrongly....

once i corrected it it wrks fine the 8th char is on the first line ,and the 9th at 0X40 as you said

thanks again

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