from machine import Pin
import utime
led_0=Pin(12,Pin.OUT)
led_1=Pin(13,Pin.OUT)
led_2=Pin(14,Pin.OUT)
led_3=Pin(15,Pin.OUT)

while True:
    
    led_0.value(1)
    utime.sleep(.2)
    led_0.value(0)
    utime.sleep(.2)
    led_1.value(1)
    utime.sleep(.2)
    led_1.value(0)
    utime.sleep(.2)
    led_2.value(1)
    utime.sleep(.2)
    led_2.value(0)
    utime.sleep(.2)
    led_3.value(1)
    utime.sleep(.2)
    led_3.value(0)