from machine import Pin
from time import sleep

led1 = Pin(18, Pin.OUT)
led2 = Pin(19, Pin.OUT)
led3 = Pin(20, Pin.OUT)
buz = Pin(21, Pin.OUT)

def ledBlink(le):
  le.on()
  sleep(0.5)
  le.off()
  sleep(0.5) 

while True:
  ledBlink(led1)
  ledBlink(led2)
  ledBlink(buz)
  ledBlink(led3)
  ledBlink(led2)
  ledBlink(buz)