from machine import Pin
import time

led1 = Pin(9, Pin.OUT)
led2 = Pin(10, Pin.OUT)
led3 = Pin(11, Pin.OUT)

while True:
    led1.value(1)
    time.sleep(0.2)
    led1.value(0)

    led2.value(1)
    time.sleep(0.2)
    led2.value(0)

    led3.value(1)
    time.sleep(0.2)
    led3.value(0)