import time 
from machine import Pin
 
pins=[15,2,13,4,5,18,19,21,22,23]

def showled():
    length=len(pins) 
    for i in range(0,length):
        led=Pin(pins[i],Pin.OUT) 
        led.value(1) 
        time.sleep_ms(500) 
        led.value(0)



while True:

    showled()