import utime
from machine import Pin
onboard_led1=Pin(1,Pin.OUT)
onboard_led2=Pin(16,Pin.OUT)
onboard_led3=Pin(18,Pin.OUT)
while True:
  onboard_led1.toggle()
  utime.sleep(3)
  onboard_led2.toggle()
  utime.sleep(3)
  onboard_led3.toggle()