;
; control the light connected to the pwm output pins
;
; author: hackbard@hackdaworld.org
;

; specify device
.include "../include/2313def.inc"

; for register/bit definitions compatibility
.include "./s90_to_tiny.inc"

; ------------------
; interrupt vectors:
; ------------------

; reset
rjmp INIT
; int0
rjmp INT_ROUTINE
; int1
reti
; timer 1 capture
reti
; timer 1 compare
reti
; timer 1 overflow
reti
; timer 0 overflow
reti
; usart rx complete
rjmp UART_RX
; usart data register empty
reti
; usart tx complete
reti
; analog comperator
reti
; pin change interrupt
reti
; timer/counter 1 compare match b
reti
; timer/counter 0 compare match a
reti
; timer/counter 0 compare match b
reti
; usi start condition
reti
; usi overflow
reti
; eeprom ready
reti
; watchdog timer overflow
reti

; -----
; code:
; -----

INIT:
	; set stackpointer
	ldi r16,low(RAMEND)	; write top of ramend (lowbyte)
	out SPL,r16		; to stackpointer

	; rs232 init
	ldi r16,0
	out UBRRH,r16
	ldi r16,12 	; "38.4k bps @ 8 mhz" / "4.8k bps @ 1 mhz"
	out UBRRL,r16 	; write to uart baudrate register
	ldi r16,(1<<RXEN)|(1<<TXEN)|(1<<RXCIE)	; enable rx/tx + rx interrupt
	out UCSRB,r16	; write to uart control register

	; int0
	ldi r16,(1<<PD2)	; int0 input
	out DDRD,r16
	ldi r16,(1<<PD2)	; int0 pull-up
	out PORTD,r16
	ldi r16,0		; interrupt on low level of int0
	out MCUCR,r16
	ldi r16,(1<<INT0) 	; ir enable
	out GIMSK,r16

	; port config
	ldi r16,0		; output
	out DDRB,r16
	ldi r16,0xff		; pull high
	out PORTB,r16

	; some initial values
	ldi r20,0
	ldi r17,0xff
	ldi r25,0x4c

	; global interrupt enable
	sei

MAIN:
	out PORTB,r17
	
	rjmp MAIN


UART_RX:
	in r29,UDR
	UART_OUT:
		sbis UCSRA,UDRE
		rjmp UART_OUT
		out UDR,r29
	reti


INT_ROUTINE:
	ldi r16,0		; disable int0
	out GIMSK,r16
	cpi r17,0xff 		; toggle light
	breq TURN_ON
	TURN_OFF:
		ldi r17,0xff	; turn off light
		ldi r25,0x44	; D
		rjmp CONTINUE
	TURN_ON:
		ldi r17,0	; turn on light
		ldi r25,0x4c	; L
	CONTINUE:
		out PORTB,r17
		sbis UCSRA,UDRE
		rjmp CONTINUE
		out UDR,r25
	ldi r20,0
	WAIT:
		ldi r21,0
		WAIT_II:
			inc r21
			cpi r21,0xff
			brne WAIT_II
		inc r20
		cpi r20,0xff
		brne WAIT

	ldi r16,(1<<INT0) ; (re)activate int0
	out GIMSK,r16

	reti
		
; eof