Problems with 18F458

[Russian]

Hi everyone, I hope I can get some help on this great forum! =)

I have recently moved from PIC16F18 to PIC18F458, and I have remade one of my old programs for testing with the new processor. The program is supposed to write som text on a standart HD44780 LCD, and it worked fine on the 16F84. When I now connect my LCD to 18F458, the screen shows the last to symbols of the text string in the start of line 1, the screen also flickers in a wierd way, and the cursor is blinking, although I turn it off in the program. Sometimes when I get my fingers close to the processor, or the quartz crystal the screen goes baserk and starts writing some nonsense on both lines (still flickering). I don't know whats worng, since I have everything correctly connected and everything. I don't think, that it could be the program, because I tried with the simpliest thing (two flashing LED's) and it also worked out kindda wierd...Any ideas? Thanks, any help will be appreciated!

Regards Denis

[CocaColaKid]

What does your code look like? What pins is the LCD connected to? What are you using for an oscillator?

[Russian]

I use a 4 Mhz crystal as osc. and I use PORTB as output, this is what my code looks like, I have included the library for LCD in the txt file:

LIST p=18F458 ;tell assembler what chip we are using
include "p18f458.inc" ;include the defaults for the chip
ERRORLEVEL 0, -302 ;suppress bank selection messages

cblock 0x20 ;start of general purpose registers
;LCD
count ;used in looping routines
count1 ;used in delay routine
counta ;used in delay routine
countb ;used in delay routine
tmp1 ;temporary storage
tmp2 templcd ;temp store for 4 bit mode
templcd2

endc

LCD_PORT Equ PORTB
LCD_TRIS Equ TRISB
LCD_RS Equ 0x04
LCD_RW Equ 0x06
LCD_E Equ 0x07


;--------Program-------------------


SetPorts
movlw 0x00 ;make all pins outputs
movwf LCD_TRIS ;wait for LCD to settle
call Delay100
call LCD_Init ;setup LCD
call LCD_CurOff

ld
call LCD_Line1
movlw 'H'
call LCD_Char
movlw 'e'
call LCD_Char
movlw 'l'
call LCD_Char
movlw 'l'
call LCD_Char
movlw 'o'
call LCD_Char
movlw ' '
call LCD_Char
movlw 'W'
call LCD_Char
movlw 'o'
call LCD_Char
movlw 'r'
call LCD_Char
movlw 'l'
call LCD_Char
movlw 'd'
call LCD_Char
movlw '!'
call LCD_Char
movlw '!'
call LCD_Char
movlw '!'
call LCD_Char

endprg goto endprg


include <lcd.lib>


;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

end

[NavMicroSystems]

Russian,

Do you have a pullup resistor on MCLR ?

And hey, this is a PICBASIC Forum !

[CocaColaKid]

Sorry but assembly is greek to me.

[Felch]

Did you configure your 18f458 correctly? Especially LVP_OFF! This was the mistake, i made.
Here is my code, check for the LCDPUTCHAR routine.