from machine import Pin
from time import sleep

while True:
    for j in range(1,6,1):
        led = Pin(j,Pin.OUT)
        led.value(1)
        sleep(0.3)
        led.value(0)
    for j in range(4,1,-1):
        led = Pin(j,Pin.OUT)
        led.value(1)
        sleep(0.3)
        led.value(0)