Put some delays (a few tens of milliseconds) between each command.
 It takes time for the 44780 to initialize.   I am assuming you don't
 already have some delays as you didn't say anything about them.

                                              Regards,

                                                Jim





> Greetings,
>
> I'm new to this list and was wondering if someone could assist me in
> determining if I've done
>something "really, really, bad (tm)" to the Optrex LCD 16x2 display I'm
>trying to interface to a Microchip 16F876.
>
> I hooked it up according to the datasheet, and ever since the first
> time it has been powered on, the first line goes all black
> (all solid / non-blinking cursor characters).  Adjusting the contrast
> yields a lighter/darker all black first line.  The second line isn't
> on, ever.
>
> Any and all attempts to get it to initialize have failed.  I've tried
> the auto-init with a delayed power-on (using a RC circuit).
> I've tried initialization using my own code in 4-bit mode, which I've
> stepped through a line at time with the ICD, and watched the pins go
> high/low with a voltmeter appropriately as I stepped through the code
> with the ICD.  Everything SEEMS to be correct (as in, each line of the
> supplied specs for initialization is sent), but alas, I know something
> is wrong.  The question is what? :-(
>
> Finally, I wired it up for 8-bit mode, and used Tony Nixon's '877
> program, only making changes so that it used PORTC and PORTB instead of
> PORTD http://www.piclist.com/techref/microchip/16F877/tlcd.asm
> (as in, my changes were minor enough, that I'm sure it didn't affect
> the program's functionality)
>
> What does an Optrex display (or one with a Hitachi LCD driver) do
> normally when powered up?
> Should I expect a blank display?  There is nothing on Optrex's website
> about this...
>
> Thanks,
> Ashraf Farrag
>
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