from machine import Pin, Timer
from utime import sleep

led_pins = [0, 1, 2, 5, 8, 7, 6, 3, 4]
leds = [Pin(pin_num, Pin.OUT) for pin_num in led_pins]

def blink_led(led):
    led.value(1)
    sleep(0.2)
    led.value(0)

def fn(t):
    for led in leds:
        blink_led(led)

tim = Timer(mode=Timer.PERIODIC, freq=1, callback=fn)