;-----------------------------------------------------------;
; LED optical detector
;-----------------------------------------------------------;

.include "tn11def.inc"
.include "avr.inc"

;----------------------------------------------------------;
; Interturpt Vector

.cseg
	; Interrupt Vectors (ATtiny11)
;	rjmp	reset		; Reset
;	rjmp	isr_int0	; Extrenal INT0
;	rjmp	isr_pci		; Pin Change
;	rjmp	isr_t0_ovf	; TC0 overflow
;	rjmp	isr_aci		; Analog comparator

;----------------------------------------------------------;
; Program Code

reset:
	sbi	PORTB, 2	;PB2="H" (Monitor)
	sbi	DDRB, 2		;/

	cbi	PORTB, 0	;LED OFF, Discharge Cs
	rjmp	PC+1		;
	rjmp	PC+1		;/
	cbi	DDRB, 0		;PB0 as input (Photo Diode)

	ldiw	Z, 2200/6	;Wait until voltage on PB0 reaches PB1 in time out of 2ms
	sbic	ACSR, ACO	; Has PB0 reached PB1? (Light?)
	rjmp	PC+5		; /break with LED OFF
	subiw	Z, 1		; Timeout occured? (Dark?)
	brne	PC-4		; 
	sbi	PORTB, 0	; /break with LED ON

	cbi	PORTB, 2	;PB2="L" (Monitor)

	sbi	DDRB, 0		;PB0 as output (LED)

	ldiw	Z, 11000/4	;Delay 10ms
	subiw	Z, 1		;
	brne	PC-2		;/

	rjmp	reset