from machine import Pin
from time import sleep
led1=Pin(2,Pin.OUT)
led2=Pin(4,Pin.OUT)
led3=Pin(5,Pin.OUT)
while True:
  led1.value(1)
  sleep(3)
  led1.value(0)
  sleep(3)
  led2.value(1)
  sleep(1.5)
  led2.value(0)
  sleep(1.5) 
  led3.value(1)
  sleep(3)
  led3.value(0)
  sleep(3)
 CAI KHAC:
  while True:
    buttonStatus = btn.value(0)
    print (buttonStatus)