from machine import Pin
import time

A1 = Pin(12, Pin.OUT)
A2 = Pin(13, Pin.OUT)
B1 = Pin(14, Pin.OUT)
B2 = Pin(15, Pin.OUT)

b1 = Pin(16, Pin.IN, Pin.PULL_UP)
b2 = Pin(18, Pin.IN, Pin.PULL_UP)

Motor = [A1, A2, B1, B2]

secuencia = [[1, 0, 1, 0],[1, 0, 0, 1],[0 , 1, 0, 1], [0, 1, 1, 0] ]

def  salida(valor):
    for k in range(4):
        Motor[k].value(secuencia[valor][k])

conta = 0
salida(conta)

ini1 = time.ticks_ms()
ini2 = time.ticks_ms()

def  fun_b1(b1):
    global conta, ini1

    fin = time.ticks_ms()
    if time.ticks_diff(fin, ini1) < 250:
        ini1 = fin
        return

    conta += 1
    if conta == 4:
        conta = 0
    salida(conta)
    ini1 = fin

def  fun_b2(b2):
    global conta, ini2
    
    fin = time.ticks_ms()
    if time.ticks_diff(fin, ini2) < 250:
        ini2 = fin
        return

    conta -= 1
    if conta < 0:
        conta = 3
    salida(conta)
    ini2 = fin

b1.irq(trigger=Pin.IRQ_FALLING, handler=fun_b1)
b2.irq(trigger=Pin.IRQ_FALLING, handler=fun_b2)

while True:
    pass