#infinite time blink
from machine import Pin
from time import sleep

led3 = Pin(15, Pin.OUT)  
while True:
    led3.value(1)
    sleep(3)
    led3.value(0)
    sleep(3)
    
    led3.value(1)
    sleep(3)
    led3.value(0)
    sleep(3)
    print('hi')