import machine
from utime import sleep

def main():
    s0 = machine.Pin(27, machine.Pin.OUT)
    mux_in = machine.Pin(26, machine.Pin.IN, machine.Pin.PULL_DOWN)
    button = machine.Pin(16, machine.Pin.IN, machine.Pin.PULL_DOWN)

    last_deci_val = 0
    last_but_state = 0
    while True:
        decimal_val = 0
        for selector_val in range(2):
            s0.value(selector_val % 2)
            sleep(2)
            decimal_val += (pow(2, selector_val) * mux_in.value())

        if last_deci_val != decimal_val:
            last_deci_val = decimal_val
            print(f'selected output: {last_deci_val}')
        sleep(0.1)

        if last_but_state != button.value():
            last_but_state = button.value()
            print(f'current button state: {last_but_state}')
            sleep(0.2)

if __name__ == "__main__":
    main()