arduino_assembly_blink.asm

;
; arduino_assembly_blink.asm
;
; Created: 21/10/2019 18:58:07
; Author : Giovanni Vangelista
; Site: https://www.make4future.com

;Turns an LED on for 100ms, then off for 100ms, repeatedly.
;This program use a on-board LED of your arduino. On the arduino UNO, NANO, MEGA and ZERO it is attached to digital pin 13 (PB5)

    ldi r16,0B00000000 ;write on the register r16 a binary value
    ldi r17,0B00100000

    out DDRB,r17 ;Set the port out equal to the r17 value (1=output;0=input)

Start:


    out PortB,r17 ;scrivo su portX i valori del registro rX
    call timer  ;call subroutine named 'timer'
    out PortB,r16
    call timer

    rjmp Start  ;go to 'Start'



timer:  ;subroutine of delay (100ms)
    ldi  r18, 9
    ldi  r19, 30
    ldi  r20, 229
L1: dec  r20
    brne L1
    dec  r19
    brne L1
    dec  r18
    brne L1
    nop
    ret ;return from subroutine