PIC + MOP 2X8 no worky.

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BMN
LCD?
Posts: 3
Joined: Mon Apr 02, 2007 10:17 pm

PIC + MOP 2X8 no worky.

Post by BMN »

I saw this forum was empty so I decided to start it off. So, here's the background. After several months of having my MOP-AL82B-BYFY-25J-3IN sitting on my shelf I finally got around to trying to get it to work with a PIC project of mine.

I gone over the wiring and it's correct, but I just can't get it to quite work. I've followed the 8 bit flow chart on initialization and just can't get a cursor or a letter to show up. Here's a c/p of the code below. Maybe someone can see if I messed up somewhere. The clock speed on the chip is coming from a freq generator at 100Hz so I can watch things work slow so I'm pretty sure that it's not a high speed timing issue. I believe it's a step or two I don't know about.

Thanks in advance.

Oh, and I have the R/W line tied to ground for the time being in case you notice nothing about it in the code.

*****************************


#DEFINE E PORTC, 4
#DEFINE RS PORTC, 5
#DEFINE LCD PORTB
#DEFINE VOLT PORTC, 2
#DEFINE LED PORTC, 3

LIST R=DEC
INCLUDE "P16F870.INC"
CBLOCK 0x020

ENDC
ORG 0
MAINLINE



BCF STATUS, RP0
BCF STATUS, RP1
CLRF PORTA
CLRF LCD
CLRF PORTC



BSF STATUS, RP0



MOVLW 0X00
MOVWF (TRISA^ 0x080)
MOVWF (TRISB^ 0X080)
MOVWF (TRISC^ 0x080)


BCF STATUS, RP0



; INITIALIZE

; FUNTION SET
BSF VOLT; Activates logic power after ports get cleared.
NOP
NOP
NOP
BSF LED;Lets me see when I reach this spot.
BCF RS

BSF E
MOVLW 0X038
MOVWF LCD
BCF E

NOP
NOP

BSF E
MOVLW 0X038
MOVWF LCD
BCF E





; DISPLAY OFF
BSF E
MOVLW 0X008
MOVWF LCD
BCF E

NOP
NOP

; CLEAR DISPLAY
BSF E
MOVLW 0X001
MOVWF LCD
NOP

BCF E

nop
NOP

; DISPLAY ON
BSF E
MOVLW 0X0C
MOVWF LCD
NOP

BCF E

; MODE SET
BSF E
MOVLW 0X06
MOVWF LCD
NOP

BCF E

NOP
NOP
NOP
NOP
NOP
NOP


; WRITE "H"
BSF RS
BSF E
MOVLW 0X42
MOVWF LCD

BCF E
BCF RS

LOOP
NOP
NOP
GOTO LOOP
END

Raquel
Matrix Orbital
Matrix Orbital
Posts: 796
Joined: Thu Aug 19, 2004 3:37 pm
Location: MO Office

Post by Raquel »

Hello BMN,

Thanks for your post.

It's been a while since I last wrote assembly, so I might take a little longer to help you; but I would like to note now that you might not want to ground R/W since there will be times when you will need to read the display for its busy flag.

Best Regards,
Raquel Malinis
Design and Development
Matrix Orbital

BMN
LCD?
Posts: 3
Joined: Mon Apr 02, 2007 10:17 pm

Post by BMN »

I noticed that it would be used latter on and thanks for making sure I was aware of it. Just trying to eliminate as many variables as I can before I crunk em all up.

Thanks for the help. It is most appreciated.

BMN
LCD?
Posts: 3
Joined: Mon Apr 02, 2007 10:17 pm

Post by BMN »

OK, due to tax season, I was not able to work with it any until now, but..... still no worky.

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