initialize a 20x4 LCD from hantornix using PIC 16f628

[nicolas21]

hello , my riends and i are trying to initialize a 20x4 LCD from hantornix using PIC 16f628 but no matter what assambler code we tiped in it didn´t work. All we are getting is a screen full of black squares. if anybody has an idea more than welcome to hear it
Thanks

[skimask]

hello , my riends and i are trying to initialize a 20x4 LCD from hantornix using PIC 16f628 but no matter what assambler code we tiped in it didn´t work. All we are getting is a screen full of black squares. if anybody has an idea more than welcome to hear it
Thanks

1st step - http://www.picbasic.co.uk/forum/showthread.php?t=1742

[mister_e]

Make sure your timing is right, R/W line is tied to ground. Use a pot (usually <20K works a treat) on Vo a play a little bit with the contrast.

If you use any pins on PORTA, make sure you have disabled the comparators. Somewhere in your code you should have something like..

BANKSEL CMCON
MOVLW .7
MOVWF CMCON

Your config fuse line should also be well written. Hard to tell what's wrong, no code... and asm on a Melabs PICBasic forum ;)

However i already did one here awhile back... maybe you want to try it?
see attachement. It's no way optimized, no way the best method, but may have some interesting thoughts in.

Enjoy!