;CERBERES : MINI ROBOT WITH IR EYES ;

;USES PIC16F84 µCONTROLLER ;

;WRITTEN IN MICROCHIP ASSEMBLY USE MPASM ASSEMBLER FROM MPLAB Qariya.com ;

;MPLAB CAN BE DOWNLOADED FROM WWW.MICROCHIP.COM ;



;***SET UP THE CONTANTS & VARIABLES****



LIST P=16C84

ERRORLEVEL -302 ;SUPPRESS BANK SELECTION MESSAGES



STATUS EQU H'03' ;STATUS REGISTER

TRISB EQU H'86' ;TRISB REGISTER FOR SETUP OF PORTB

PORTB EQU H'06' ;PORTB REGISTER TO DRIVE PORT B

COUNT1 EQU H'0C' ;COUNT VARIABLE 1 IS IN GENERAL PURPOSE REG 08H

COUNT2 EQU H'0D' ;COUNT VARIABLE 2 IS IN GENERAL PURPOSE REG 09H



;***SET UP PORT B IN & OUTPUT****

BSF STATUS,5 ;SWITCH TO BANK0 TO SET UP PORT B

MOVLW B'11110000' ;RB7,6,5,4 IS INPUT

MOVWF TRISB ;RB3,2,1,0 IS OUTPUT

BCF STATUS,5 ;SWITCH BACK TO BANK0 TO USE PORT B



;***MAIN PROGRAM****

START MOVLW B'00000101' ;MAKE RB0&2 HIGH: MOVE FORWARD

MOVWF PORTB ;

MOVLW H'FE' ;RESET COUNT1 TO 254

MOVWF COUNT1 ; 

MOVLW H'FE' ;RESET COUNT2 TO 254

MOVWF COUNT2 ;

BTFSS PORTB,5 ;CHECK RB5 (INPUT); IF IT IS LOW

CALL BACKL ;THEN EXECUTE BACKLEFT ROUTINE

BTFSS PORTB,6 ;CHECK RB6 (INPUT); IF IT IS LOW

CALL BACKR ;EXECUTE BACKRIGHT ROUTINE

GOTO START ;RETURN TO LABEL START



;***BACKLEFT ROUTINE****

BACKL MOVLW B'00001010' ;MAKE RB1&3 HIGH: MOVE BACKWARD

MOVWF PORTB ;

CALL DELAY ;

MOVLW B'00001001' ;MAKE RB2&3 HIGH: ROTATE LEFT

MOVWF PORTB ;

CALL DELAY ;

RETURN

;***BACKRIGHT ROUTINE****

BACKR MOVLW B'00001010' ;MAKE RB1&3 HIGH: MOVE BACKWARD

MOVWF PORTB ;

CALL DELAY ;

MOVLW B'00000110' ;MAKE RB2&3 HIGH: ROTATE RIGHT

MOVWF PORTB ;

CALL DELAY ;

RETURN



DELAY MOVLW H'EE' ;RESET ALL COUNTER VARIABLES

MOVWF COUNT1 

MOVLW H'99' 

MOVWF COUNT2



LOOP1 CLRWDT ;RESET THE WATCHDOG TIMER

DECFSZ COUNT1,1 ;this is a delay loop 

GOTO LOOP1 ;tuned to make Cerberes 

DECFSZ COUNT2,1 ;turn about 90 degrees

GOTO LOOP1 

RETURN



END;