from machine import Pin 
from time import sleep
bt1=(15,Pin.OUT,Pin.ouT)
led(1)=Pin(21,Pin.OUT)
led(2)=Pin(22,Pin.Out)
led(3)=Pin(23,Pin.OUT)
while(True):
    led(1).value(True)
    sleep(2)
    led(1).value(False)
    sleep(2)
    led(2).value(True)
    sleep(2)
    led(2).value(False)
    sleep(2)
    led(3).value(True)
    sleep(2)
    led(3).value(False)
    sleep(2)
    if:
        led(1) .off() 
        led(2) .off() 
        led(3) .off()