from machine import Pin
from time import sleep

T1 = Pin(0, Pin.IN)
T2 = Pin(1, Pin.IN)
T3 = Pin(2, Pin.IN)
T4 = Pin(3, Pin.IN)

LED0 = Pin(4, Pin.OUT)
LED1 = Pin(5, Pin.OUT)
LED2 = Pin(6, Pin.OUT)
LED3 = Pin(7, Pin.OUT)
LED4 = Pin(8, Pin.OUT)
LED5 = Pin(9, Pin.OUT)
LED6 = Pin(10, Pin.OUT)
LED7 = Pin(11, Pin.OUT)

LED = [LED0, LED1, LED2, LED3, LED4, LED5, LED6, LED7]

def addZeros(string, length):
    while len(string) < length:
        string = "0" + string
    return string

def buttonValues(a, b, c, d):
    return T1.value() == a and T2.value() == b and T3.value() == c and T4.value() == d

counter = 0

while True:
    if buttonValues(1, 0, 0, 0) and counter < 255:
        counter = counter + 1
    elif buttonValues(0, 1, 0, 0) and counter > 0:
        counter = counter - 1
    elif buttonValues(0, 0, 1, 0):
        counter = 0
    elif buttonValues(0, 0, 0, 1):
        counter = 255

    binary = bin(counter)
    bits = addZeros(binary[2:], 8)

    for i in range(0, 8):
        LED[i].value(int(bits[i]))

    # kako bi se osiguralo okidanje samo na uzlaznu ivicu sata
    # tj. sprijecile visestruke akcije u logickoj jedinici
    while T1.value() or T2.value() or T3.value() or T4.value():
        pass

    sleep(0.2)