;
; zahlenschloss.asm
;
; Created: 15/06/2019 14:18:32
; Author : winshit
;

; naming definitions
.def Temp         = 16
.def Digit        = R20
.def Fail         = R21
.def ButtonStates = R22
.def digit1       = R25
.def digit2       = R26
.def digit3       = R27
.def digit4       = R28


; input and output pins
ldi Temp, 0b00111111
out DDRB, Temp

ldi Temp, 0b00001111
out DDRD, Temp

clr Temp
out DDRA, Temp


; init vars
ldi digit1, 0b00000000
ldi digit2, 0b00001000
ldi digit3, 0b00000001
ldi digit4, 0b00000101

; init stackpointer
ldi Temp, high(RAMEND)
out SPH, Temp
ldi Temp, low(RAMEND)
out SPL, Temp


; endless loop
MAIN:   ldi Fail, 0b00000000

        ; set light, read digit #1
        ldi Temp, 0b00000001
        out PORTB, Temp
        call POLL_BUTTONS
        cp digit, digit1
        brne INC_FAIL

        ; set light, read digit #2
        ldi Temp, 0b00000011
        out PORTB, Temp
        call POLL_BUTTONS
        cp digit, digit2
        brne INC_FAIL

        ; set light, read digit #3
        ldi Temp, 0b00000111
        out PORTB, Temp
        call POLL_BUTTONS
        cp digit, digit3
        brne INC_FAIL

        ; set light, read digit #4
        ldi Temp, 0b00001111
        out PORTB, Temp
        call POLL_BUTTONS
        cp digit, digit4
        brne INC_FAIL

        clr Temp
        cp Fail, Temp
        brne ...

        rjmp MAIN

INC_FAIL:
        inc  Fail

POLL_BUTTONS:
        ; check if increment was pressed
        in Temp, PINA
        ldi Temp, 0b10000000
        and Temp, PINA
        cpi Temp, 0
        brne COMPARE_PREV

        inc digit

        cp

COMPARE_PREV:
        cpi ButtonState, 1
        breq ldi Temp, 1

LED_SUCCESS:
        ldi Temp, 0b00010000
        out PORTB, Temp

LED_ERROR:
        ldi Temp, 0b00100000
        out PORTB, Temp