picbasic +12c508a+soft_stack error

[Bruce]

Any chance we can see that 12-byte cylon scanner?

[Darrel Taylor]

Sure,

The 12-byte version is toward the end on page 2.
http://www.sfcompiler.co.uk/forum/viewtopic.php?t=72

Edit: Hey, you were there to.
<br>

[Bruce]

Yipes I totally forgot that one. That was way interesting and the end result was really creative.

Nice work DT..;o}

Tim B and I got into one of these a long time back, and here's one he came up with.

Can we beat this without EEPROM?

Standard cyclone thingie moving the LED back & forth with ~1S delay periods.

  	list      p=16F628A
	#include "P16F628A.inc"
	errorlevel  -302        ; suppress message 302 from list file
	__CONFIG _CP_OFF & _BODEN_ON & _MCLRE_ON & _WDT_ON & _PWRTE_ON & _LVP_OFF & _INTOSC_OSC_NOCLKOUT

	movlw	0x01
	movwf	PORTB	     ; Set Portb,0
	bsf	STATUS,RP0   ; Bank 1
	clrf	TRISB	     ; RB all outputs
	bcf	OPTION_REG,0 ; 1:64 prescaler to WDT
	bcf	STATUS,RP0   ; Bank 0

Left
	sleep		    ; go to sleep for 64 * 18mS ~1 second
	rlf	PORTB,F     ; rotate bit across portb from lsb to msb
	btfss	PORTB,7     ; jump to Right after Portb,7 = 1
	goto	Left
	
Right
	sleep		    ; go to sleep for 64 * 18mS ~1 second
	rrf	PORTB,F     ; rotate bit across Portb from msb to lsb
	btfss	PORTB,0     ; jump back to left after Portb,0 = 1
	goto	Right       ; loop until Portb,0 = 1
	goto	Left        ; now rotate back to the left.
	
    End

[mister_e]

seems to be hardly optimized to me

food for thought... let's see...

[Darrel Taylor]

Tim's compiled to 15 words.

Here's 13 ... &nbsp; Note: LED's go to VDD

    list      p=16F628A
    #include "P16F628A.inc"
    errorlevel  -302        ; suppress message 302 from list file
    __CONFIG _CP_OFF & _BODEN_ON & _MCLRE_ON & _WDT_ON & _PWRTE_ON & _LVP_OFF & _INTOSC_OSC_NOCLKOUT

    clrf    PORTB         ; PORTB all 0's
    bsf	    STATUS,RP0    ; Bank 1
    bcf	    OPTION_REG, 0 ; 1:64 prescaler to WDT
    bcf     TRISB, 0      ; set RB0 to output
    bsf     STATUS, C     ; set carry flag for rotation
Loop
    btfss   TMR2, 3       ; switch Left/Right every 8 times
    rlf	    TRISB,F       ; rotate Left across TRISB
    btfsc   TMR2, 3
    rrf     TRISB,F       ; rotate Right across TRISB
    btfsc   STATUS, C     ; No sleep if output rotated into carry
    sleep                 ; nite nite
    incf    TMR2          ; Timer2 used for it's 00 value on reset.
    goto    Loop          ; Repeat

EDIT: Rats!
While it works in MPSIM, it's not going to do it on the real thing.
Time for a breadboard.

<br>

[Darrel Taylor]

OK, ignore the last one. That's what I get for using a simulator.

This is 14 WORDS, 1 less than Tim's.
At least it beats him

    list      p=16F88
    #include "P16F88.inc"
    errorlevel  -302        ; suppress message 302 from list file
    __CONFIG  _CONFIG1, _XT_OSC & _CP_OFF & _BODEN_ON & _MCLR_ON & _WDT_ON & _PWRTE_ON & _LVP_OFF

    clrf    PORTB         ; PORTB all 0's
    bsf     STATUS,RP0    ; Bank 1
    bcf     OPTION_REG, 0 ; 1:64 prescaler to WDT
    bcf     TRISB, 0      ; RB0 output
Loop
    sleep                 ; nite nite

    btfss   SPBRG,0       ; SPBRG used for it's 00 reset value   
    rlf     TRISB,F       ; rotate Left across TRISB
    btfsc   SPBRG,0
    rrf     TRISB,F       ; rotate Right across TRISB
    
    btfss   TRISB, 7      ; At LED7? - go the other way
    incf    SPBRG,F
    btfss   TRISB, 0      ; At LED0? - go the other way
    incf    SPBRG,F 
    
    goto    Loop          ; Repeat

LED's go to VDD.
Tested, working on 16F88, should be the same (except configs) on 16F628A.
<br>

[mister_e]

yup.. hence why i never trust sim...