; This is the test one for the PIC Nintendo joystick
;
;
; Written by:Steven Easley
; Email: seasley@robotdungeon.com
; Webpage: www.robotdungeon.com 
;
;
;

	LIST	p=16F84a
	INCLUDE	"p16f84a.inc"
	__CONFIG _PWRTE_ON & _HS_OSC & _WDT_OFF & _CP_OFF 
	errorlevel	-302 
 
; The defines
#DEFINE clock 	PORTA,0		;Red wire from controller
#DEFINE dat 	PORTA,1		;Yellow wire from controller
#DEFINE perser 	PORTA,2		;Orange wire from controller

;Define the outputs that goto the CMOS switches
#DEFINE	right	PORTB,0
#DEFINE	left	PORTB,1
#DEFINE	up		PORTB,2
#DEFINE	down	PORTB,3
#DEFINE	but_A	PORTB,4
#DEFINE	but_B	PORTB,5
#DEFINE	select	PORTB,6
#DEFINE	start	PORTB,7


	cblock 0x14
		current
		counter
	Endc

;Define ram locations
	org	0
	goto	init

;Setup stuff
init
	bsf		STATUS, RP0
	movlw	b'00000010'
	movwf	TRISA
	clrf	TRISB
	bcf		STATUS, RP0
	clrf	PORTB
	clrf	PORTA

;This is the main program
main
	;Nobuttons prossed default is b'00000101'

	call	readdat
	call	scan_dat
	goto	main



scan_dat
chk_right	;check right
	btfss	current,0
	goto	right_pressed
	bsf		right
	goto	chk_left
right_pressed
	bcf		right

chk_left	;check left	
	btfss	current,1
	goto	left_pressed
	bcf		left
	goto	chk_down
left_pressed
	bsf		left		

chk_down	;check down	
	btfss	current,2
	goto	down_pressed
	bsf		down
	goto	chk_up
down_pressed
	bcf		down	

chk_up		;check up	
	btfss	current,3
	goto	up_pressed
	bcf		up
	goto	chk_start
up_pressed
	bsf		up	

chk_start	;check start	
	btfss	current,4
	goto	start_pressed
	bcf		start
	goto	chk_select
start_pressed
	bsf		start	

chk_select	;check select	
	btfss	current,5
	goto	select_pressed
	bcf		select
	goto	chk_but_B
select_pressed
	bsf		select

chk_but_B	;check but_B	
	btfss	current,6
	goto	but_B_pressed
	bcf		but_B
	goto	chk_but_A
but_B_pressed
	bsf		but_B

chk_but_A	;check but_A	
	btfss	current,7
	goto	but_A_pressed
	bcf		but_A
	goto	end_scan
but_A_pressed
	bsf		but_A

end_scan
	return





readdat
	bcf		clock
	bcf		perser
	bsf		perser
	bsf		clock
	bcf		clock
	bcf		perser
	movlw	d'8'
	movwf	counter
	movlw	d'0'
	
getbits
	bcf		STATUS, C
	btfsc	dat
	bsf		STATUS, C
	rlf		current, w
	movwf	current
	bsf		clock
	bcf		clock
	decfsz	counter,f
	goto	getbits
	return

	end