LCDOUT w/custom interface?

Someone on another Forum asked me if it's possible to use the LCDOUT function with my old Novelty Serial LCD Interface (a simple 1-pin interface experiment inspired by the Predko 2-pin shift-register interface).

http://www.picbasic.co.uk/forum/atta...5&d=1253458266
The interface uses standard Async' Serial data but in a rather exotic format where each byte is sent as two bytes, one nybble per byte, along with the LCD 'RS' bit.

Code:

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;
;  host low level K8LH Novelty 12F635 Serial LCD Driver
;
LcdCmd
        clrc                    ; C = RS = 0, 'command'          |B0
        skpnc                  ;                                |B0
LcdDat
        setc                    ; C = RS = 1, 'data'              |B0
        movwf  Temp            ; save data in WREG              |B0
        swapf  Temp,W          ; swap nybbles -> WREG            |B0
        call    LcdNyb          ; send left nybble                |B0
        movf    Temp,W          ; send right nybble              |B0
LcdNyb
        andlw  0x0F            ; mask off left nybble            |B0
        skpnc                  ; RS = 0? yes, skip, else        |B0
        iorlw  b'11000000'    ; set the RS bits                |B0
        btfss  PIR1,TXIF      ; transmit buffer empty?          |B0
        goto    $-1            ; no, branch, else                |B0
        movwf  TXREG          ; send byte                      |B0
        return                  ;                                |B0

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Can the LCDOUT function use a custom driver like the one above (after being upgraded to catch the special $FE character)?

Kind regards, Mike

I must be missing the point. If it is wired as shown just use the normal LCDOUT. ???

How is the 2 pin or 1 pin thing you mention wired?

Hi, Dave

I think this might be some kind of serial to parallell converter ... trying to use the minimum pin count device ...

might be used for a very particular use ...

The Question was " Can I use THAT with PBP "LCDOUT" Command ??? "

so, the answer is NO ...

May be some SEROUT2 with modifier for 4 bits data out ... ( to be confirmed )

Alain

Quote:

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Originally Posted by Acetronics

May be some SEROUT2 with modifier for 4 bits data out ... ( to be confirmed )

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OK, I see what I was missing now. This is a LCD Backpack thing.
Interesting...

RA4 is an open drain output.
You'll need a pull-up resistor on that pin.