from machine import Pin
import utime

led1=Pin(0,Pin.OUT)
led2=Pin(1,Pin.OUT)
led3=Pin(2,Pin.OUT)

while True:
    led1.value(1)
    led2.value(0)
    led3.value(0)
    utime.sleep(1)

    led1.value(0)
    led2.value(1)
    led3.value(0)
    utime.sleep(1)

    led1.value(0)
    led2.value(0)
    led3.value(1)
    utime.sleep(1)