import machine
import time


s0 = machine.Pin(28, machine.Pin.OUT) 
s1 = machine.Pin(27, machine.Pin.IN)   
mux_in = machine.Pin(26, machine.Pin.IN)
button_pins = {
    "B0": machine.Pin(18, machine.Pin.IN),
    "B1": machine.Pin(17, machine.Pin.IN),  
    "B2": machine.Pin(16, machine.Pin.IN)  
}

led_pins = [machine.Pin(pin_num, machine.Pin.OUT) for pin_num in range(9)]





def set_led(number, state):
    led_pins[number].value(state)




for led in led_pins:
    led.value(0)  


last_dec_val=-1
while True:
    decimal_val=-1
    bit_number=0
    for selector0_val in range(2):
        s0.value(selector0_val%2)
        for selector1_val in range(2):
            s1.value(selector1_val)
            decimal_val +=(pow(2,bit_number)*mux_in.value())
            bit_number+=1
            time.sleep(0.02)
    if last_dec_val != decimal_val:
        last_dec_val=decimal_val
        print("selected output: ",last_dec_val)        


   
   

    time.sleep(0.1)