need help on display problem

[skimask]

i ve recheck all the wiring..n its all just like the diagram..n ive also have check the define as what u have advice me..but now..my lcd do display something..a gud news for me..but the bad news is..it keep displays 2 line of black boxes..why is that happen?

But...have you varied the voltage on the contrast pins...like I said in the post above!
In my experience, 2 rows of black boxes sometimes indicates not enough start up time.

[sixty9sandals]

But...have you varied the voltage on the contrast pins...like I said in the post above!
In my experience, 2 rows of black boxes sometimes indicates not enough start up time.

hi skinmask

ive done as what u advice me..adjusting the contrast value of the lcd..still..it wont work..either it wont display anything or the sreen slowly turn into black box..so..now im looking for its start time as u say it might have not enough time..so..can u advice on how to solve its time..ive put of LCD_INITMS 5000 and several pause value 5000..still i cant work..

[skimask]

hi skinmask

ive done as what u advice me..adjusting the contrast value of the lcd..still..it wont work..either it wont display anything or the sreen slowly turn into black box..so..now im looking for its start time as u say it might have not enough time..so..can u advice on how to solve its time..ive put of LCD_INITMS 5000 and several pause value 5000..still i cant work..

Screen slowly turn into black box.
Sounds like a power problem of some sort to me. Double check the datasheet, you might need a negative voltage on the contrast pin.

LCD_INITMS? Where'd you get this from?

[sixty9sandals]

Screen slowly turn into black box.
Sounds like a power problem of some sort to me. Double check the datasheet, you might need a negative voltage on the contrast pin.

LCD_INITMS? Where'd you get this from?

sory for the misunderstanding..what i mean for the screen slowly turn into black row is when im trying to adjust the pot value which is the lcd contrast value..as ive learn from the online tutorial, it mention to adjust the pot for the contrast by turn off, adjust and turn it on back..so the result is the box become darkest every time im increase the pot value... LCD_INITMS? this define was advice to me by some other expert people like u..which use to give some delay during initialise. even i never see it on any tutorial but amazingly its been recognize by microcode..n as an addition he had advice me that by compiling my source using Micro, i have to chop off the ADC section.

[skimask]

sory for the misunderstanding..what i mean for the screen slowly turn into black row is when im trying to adjust the pot value which is the lcd contrast value..as ive learn from the online tutorial, it mention to adjust the pot for the contrast by turn off, adjust and turn it on back..so the result is the box become darkest every time im increase the pot value... LCD_INITMS? this define was advice to me by some other expert people like u..which use to give some delay during initialise. even i never see it on any tutorial but amazingly its been recognize by microcode..n as an addition he had advice me that by compiling my source using Micro, i have to chop off the ADC section.

DEFINE LCD_INITMS...if you think that's recognizable by the compiler, try:

DEFINE LCD_LOADOFCRAPFORTROUBLESHOOTINGMS 1

Now what?

[Archangel]

Hi sixty9sandals,
Did you ground the RW pin ?

[sixty9sandals]

Hi sixty9sandals,
Did you ground the RW pin ?

hi joe..
ya..ive ground it..together with the vss pin.,

[sixty9sandals]

DEFINE LCD_INITMS...if you think that's recognizable by the compiler, try:

DEFINE LCD_LOADOFCRAPFORTROUBLESHOOTINGMS 1

Now what?

hi skimask...
ya..u absolutely rite..my bad..by reading the previous tread send by others..is it possibly coz by using the port d as the data lines?

[skimask]

hi skimask...
ya..u absolutely rite..my bad..by reading the previous tread send by others..is it possibly coz by using the port d as the data lines?

Nah, Port D is what everybody uses by default unless they've got some reason to use another port.

Which LCD module are you using, part number?

And is this correct:

LCD D0-D7 on PortD.0-PortD.7 (make sure you've got the order correct 0-0, 1-1, 2-2, etc)

LCD A0 on PortC.2

LCD E on PortC.3

LCD R/W grounded

You aren't setting C.2 and C.3 to outputs directly, but PBP should handle that for you.

You did say you were using the 16F877. Are you sure your programmer is set for the 16F877 and not the F877A? Can you rewrite the code and make an LED blink or anything. Who knows...maybe the thing isn't even running.