/*
light dimmer na nekom pinu pomocu timera, tako da se intenzitet svijetla mijenja promjenom omjera popunjenosti (DC-om),
treba priložiti proračun svega
*/

.def tmp = r16
.def step = r17
.def ocval = r18
.equ delayCnt = 10
.cseg
    rjmp reset

reset:
    ldi tmp, high(RAMEND)
    out SPH, tmp
    ldi tmp, low(RAMEND)
    out SPL, tmp

    ldi tmp, 0x03
    out PORTB, tmp

    ldi tmp, 0
    out DDRB, tmp

    ldi tmp, (1 << PD5)
    out DDRD, tmp

    ldi tmp, (1 << COM1A0) | (COM1A1) | (1 << WGM10)
    out TCCR1A, tmp

    ldi tmp, (1 << WGM12) | (CS11)
    out TCCR1B, tmp

    ldi tmp, high(128)
    out OCR1AH, tmp
    ldi tmp, low(128)
    out OCR1AL, tmp

    ldi ocval, 0x00
    ldi step, 0x0A

main:
    sbis PINB, 0
        rcall smanji
    sbis PINB, 1
        rcall povecaj

    rcall delay
rjmp main

smanji:
    ldi tmp, 248
    in ocval, OCR1AL

    cpse tmp, ocval
        add ocval, step

    out OCR1AL, ocval
ret

povecaj:
    ldi tmp, 8
    in ocval, OCR1AL

    cpse tmp, ocval
        sub ocval, step

    out OCR1AL, ocval
ret

delay:
    push r17
    push r18
    push r19

    clr r17
    clr r18
    ldi r19, delayCnt

    delay_loop:
        dec r17
        brne delay_loop
            dec r18
            brne delay_loop
                dec r19
                brne delay_loop

    pop r19
    pop r18
    pop r17
ret