Problems with LCD in pic 18f8520

[HenrikOlsson]

Hi,
Shawn said what I was going to regarding setting the pins to digital, however....

I took a quick look in the BIGPIC5 manual and in the 2*16LCD section it says[quote]
The character LCD communicates with the microcontroller via 4-bit data bus[quote]
What's also noticable when you look in the manual is that the LCD is connected to PortD while you have your code setup as if the LCD was connected to PortA and PortB. So, I'm not surprised it doesn't work.... And, since it's on PortD you don't need to worry about the analog stuff.

Also, make sure that MCU-card with the 18F8720 on it have a 4Mhz x-tal. If it have something else that needs to be reflected in the code or the timing will wrong.

So, read the manual for the development board and set the code up accordingly.


Finally, it's been a while since I used LCDOUT but I don't think the part about the $fe that Shawn wrote is 100% correct. You need $fe if the next byte you send is to be interpreted as a command by the LCD, for example LCDOUT $fe,1 to clear the screen. But when writing actual data to it you should not have the $fe in there as it will then try to interpret the first character after $fe as a command and strange things will occur. LCDOUT $fe,"Hello" will interpret the H as a command (whatever that might be) and then try to print ello.

/Henrik.

[JAVEHE]

Ok thank for you time!!
I change the connection of the LCD, and i put PortD, also i change the $fe thing, but nothing happend. The only change that i see is that now the portD leds are blinking.

[HenrikOlsson]

Hi,
Did you change the individual bit assignement to match the actual hardware and changed from 8bit to 4bit?

I'd try something like this:

DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTD DEFINE LCD_RSBIT 2
DEFINE LCD_EREG PORTD
DEFINE LCD_EBIT 3
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 4000
DEFINE LCD_DATAUS 100

TRISD = %000000011

PAUSE 1000

LCDOUT $FE,1,"Hello World"  'Clear screen then print.

WHILE 1 : WEND

/Henrik.

[Acetronics2]

Hi,

the question that comes to me is ...

Which socket of the BP5 do you use for the 8 bits mode LCD ???

interesting answer ... for sure.

you should use Port J and D ... ( yess , both ! )

Alain

[Acetronics2]

That's really incredible what you can find with dedicated examples from the hardware brand ...

/*
 * Project name:
     Lcd8_Test (Demonstration of the Lcd8 Library routines)
 * Copyright:
     (c) Mikroelektronika, 2008.
 * Revision History:
     20081218:
       - initial release;
 * Description:
     This code demonstrates how to use Lcd 8-bit library. Lcd is first
     initialized, then some text is written, then the text is moved.
 * Test configuration:
     MCU:             P18F8520
     Dev.Board:       BIGPIC5
     Oscillator:      HS, 10.0 MHz
     Ext. Modules:    Lcd 2x16 module
     SW:              mikroC PRO for PIC
 * NOTES:
     - None.
*/
// Lcd8 module connections
sbit LCD8_RS at RJ2_bit;
sbit LCD8_RW at RJ3_bit;
sbit LCD8_EN at RJ4_bit;
sbit LCD8_D7 at RD7_bit;
sbit LCD8_D6 at RD6_bit;
sbit LCD8_D5 at RD5_bit;
sbit LCD8_D4 at RD4_bit;
sbit LCD8_D3 at RD3_bit;
sbit LCD8_D2 at RD2_bit;
sbit LCD8_D1 at RD1_bit;
sbit LCD8_D0 at RD0_bit;
sbit LCD8_RS_Direction at TRISJ2_bit;
sbit LCD8_RW_Direction at TRISJ3_bit;
sbit LCD8_EN_Direction at TRISJ4_bit;
sbit LCD8_D7_Direction at TRISD7_bit;
sbit LCD8_D6_Direction at TRISD6_bit;
sbit LCD8_D5_Direction at TRISD5_bit;
sbit LCD8_D4_Direction at TRISD4_bit;
sbit LCD8_D3_Direction at TRISD3_bit;
sbit LCD8_D2_Direction at TRISD2_bit;
sbit LCD8_D1_Direction at TRISD1_bit;
sbit LCD8_D0_Direction at TRISD0_bit;
// End Lcd8 module connections

Don't you think ???

Alain

No miracle, eh, my friend JAVEHE ...

[spcw1234]

Finally, it's been a while since I used LCDOUT but I don't think the part about the $fe that Shawn wrote is 100% correct. You need $fe if the next byte you send is to be interpreted as a command by the LCD, for example LCDOUT $fe,1 to clear the screen. But when writing actual data to it you should not have the $fe in there as it will then try to interpret the first character after $fe as a command and strange things will occur. LCDOUT $fe,"Hello" will interpret the H as a command (whatever that might be) and then try to print ello.

You are correct, I never use LCDOUT this way. I always have a command in there so I have never come across this problem. Thanks for correcting this