LCD display remains empty

[mat janssen]

Let us see how you connected everything from the chip to the display.
Try to adjust the background voltage, may be that is the problem!
Put a pause of 1 sec. between the declaration and your programm. Maybe the display was not yet setup.

[selbstdual]

I have not told you yet that the LCD's functionality is not proven. I was given it by someone in a waste utilization for free.

How do I figure out whether it works or not? I was able to make the lcd's points show(two rows, all matrices black). What can I conclude from that?

[Dave]

selbstdual, If you can see all black pixels then it sounds like the contrast is set too high. How do you have the contrast circuit setup? It should be at minimum a 5k pot between VCC and ground with the center wiper connected to the contrast input pin.

Dave Purola,
N8NTA

[selbstdual]

Dave, does seeing the matrices mean that the display is working at all?

[Kamikaze47]

Try adding these 2 things:

   Define OSC 20
        DEFINE	LCD_DREG PORTB
		DEFINE	LCD_DBIT 0
		DEFINE	LCD_RSREG PORTB
		DEFINE 	LCD_RSBIT 4
		DEFINE	LCD_EREG PORTB
		DEFINE	LCD_EBIT 5	
		DEFINE	LCD_BITS 4
		DEFINE	LCD_LINES 2
		DEFINE	LCD_COMMANDUS 2000
		DEFINE	LCD_DATAUS 50

                PAUSE 100
    
Go:    
    LCDOUT $FE,1,$FE,2,"Geez"
    Sleep 100
    GOTO Go

[selbstdual]

First of all I want to make sure that the lcd is working at all. How do I do that?

[Kamikaze47]

first, make sure that when you apply power, the top line of the LCD displays solid blocks. If this is the case, try the additions i suggested above.

If this is not the case, you probably need to have a contrast control for the LCD. You need a variable resistor and hook it up like this:

LCD pin 3
   |
   |   +5v
   |    |
   |    |
   |    \
   |    /
   ---->\ variable resistor (10k or bigger)
        /
        \
        |
        |
       gnd