import machine
from machine import Pin
import time

AL = Pin(7, Pin.OUT) # A-
AP = Pin(6, Pin.OUT) # A+
BP = Pin(5, Pin.OUT) # B+
BL = Pin(4, Pin.OUT) # B-

while True:
    AL.value(1)
    AP.value(0)
    BP.value(0)
    BL.value(0)
    time.sleep_ms(100)

    AL.value(0)
    AP.value(1)
    BP.value(0)
    BL.value(0)
    time.sleep_ms(100)

    AL.value(0)
    AP.value(0)
    BP.value(1)
    BL.value(0)
    time.sleep_ms(100)

    AL.value(0)
    AP.value(0)
    BP.value(0)
    BL.value(1)
    time.sleep_ms(100)