from machine import Pin, PWM
import time
p0 = Pin(16, Pin.OUT)
p1 = Pin(5, Pin.OUT)
p2 = Pin(4, Pin.OUT)
p3 = Pin(0, Pin.OUT)

A = 0
B = 1
while True:
    if B == 1:
        if A == 0:
            p0.value(0)
            p1.value(0)
            p2.value(0)
            p3.value(0)
        elif A == 1:
            p0.value(1)
            p1.value(0)
            p2.value(0)
            p3.value(0)
        elif A == 2:
            p0.value(0)
            p1.value(1)
            p2.value(0)
            p3.value(0)
        elif A == 3:
            p0.value(1)
            p1.value(1)
            p2.value(0)
            p3.value(0)
        elif A == 4:
            p0.value(0)
            p1.value(0)
            p2.value(1)
            p3.value(0)
        elif A == 5:
            p0.value(1)
            p1.value(0)
            p2.value(1)
            p3.value(0)
        elif A == 6:
            p0.value(0)
            p1.value(1)
            p2.value(1)
            p3.value(0)
        elif A == 7:
            p0.value(1)
            p1.value(1)
            p2.value(1)
            p3.value(0)
        elif A == 8:
            p0.value(0)
            p1.value(0)
            p2.value(0)
            p3.value(1)
        elif A == 9:
            p0.value(1)
            p1.value(0)
            p2.value(0)
            p3.value(1)
            
    if A == 9:
        A = 0
    else:
        A+=1
    time.sleep(2)