from machine import Pin
from time import sleep

led1 = Pin(2, Pin.OUT, value=0)
led2 = Pin(15, Pin.OUT, value=0)

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