from machine import Pin
from time import sleep

led_1=Pin(6,Pin.OUT)
led_2=Pin(28,Pin.OUT)
while True:
    led_1.value(1)
    led_2.value(0)
    sleep(1)
    led_2.value(1)
    led_1.value(0)
    sleep(1)
    led_1.value(1)
    led_2.value(0)
    sleep(1)