Need idea hove to..?

[phoenix_1]

phoenix,
Read the PBP manual, specifically the section on how to define the pins to be used for driving an LCD and your project will rise from the ashes.

Another case of RTFM...

I was probe on 2x16 chr and work fine with 4x20 don't want work .
I dont know what is problem becouse i was never use 4x20!
Any sugest
Sorry for my bad english!
Regards

[skimask]

I was probe on 2x16 chr and work fine with 4x20 don't want work .
I dont know what is problem becouse i was never use 4x20!
Any sugest
Sorry for my bad english!
Regards

Yes, a good suggestion is to re-read the PBP manual...as suggested in my last post. The define's you need are there.
Between that and the datasheet for the 16F877(a?), you should be able to figure out what is wrong.
We haven't seen any of the code you may (or may not) have written, no idea of your schematic (except for a vague idea of how you have connected your LCD, which leaves a bit to be desired), and not really much of an idea what you have tried so far.

For example, my truck's 'Check Engine' lamp is illuminated. What's wrong with it?
Not a lot of information is there?
And your English, while not perfect, is fine.

[phoenix_1]

Yes, a good suggestion is to re-read the PBP manual...as suggested in my last post. The define's you need are there.
Between that and the datasheet for the 16F877(a?), you should be able to figure out what is wrong.
We haven't seen any of the code you may (or may not) have written, no idea of your schematic (except for a vague idea of how you have connected your LCD, which leaves a bit to be desired), and not really much of an idea what you have tried so far.

For example, my truck's 'Check Engine' lamp is illuminated. What's wrong with it?
Not a lot of information is there?
And your English, while not perfect, is fine.

Here are defines:

define OSC 20
ADCON0.0 = 0
ADCON1 = 7
DEFINE LCD_DREG PORTA
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTC
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTC
DEFINE LCD_EBIT 1
DEFINE LCD_BITS 4
DEFINE LCD_LINES 4 ******************when is 2 and I use 2x16 it work 100%
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50

As you see:

LCD Wire PIC
RS --------------portc.0 -----> 4K7 pullup to +5V
E----------------portc.1
D4---------------porta.0
D5---------------porta.1
D6---------------porta.2
D7---------------porta.3

And that work 100% fine with 2x16 when I redefine No:. of lines of LCD.

[skimask]

Try increasing the 'startup pause', give the LCD more time to start itself before you start sending data. Double check your contrast wiring/voltage.

[phoenix_1]

Try increasing the 'startup pause', give the LCD more time to start itself before you start sending data. Double check your contrast wiring/voltage.

Hi skimask I was probe 1000 ms pause on startup and was probe on same pcb 2x16 chr it work and last solution is to lcd is fabric dead or bad ?!

pinout is same on 2x16 and that 4x20 and when 2x16 work and that not must be something with 4x20 wrong or maybe is problem in pbp2.50 maybe some bug ????

Really it is big problem for me...
Many thanks to all who was and will probe to help me !

Regards

p.s " The diference is only in define of no:. of lines betwin 2x16 and 4x20. and with same hardware 2x16 work and 4x20 have after reset time back all chr on screen !"

[mackrackit]

Do you have pin #3 on the display going to a pot as a voltage divider for contrast?

[phoenix_1]

Do you have pin #3 on the display going to a pot as a voltage divider for contrast?

You have 100% good question !!!!
When I was use 2x16chr display it have bad contrast and I was see TEST on it,but 4x20 have extra contrast and with same value all poligons are black at these oment I was reduce fix resistors on network on pin 3 and problem go out I can look normaly and 4x20 work fine.

The best thing is have mentors out of personal laboratory !
Other can find what you cant in your project ;-)).

The best regards to all