import time
from machine import Pin
time.sleep(0.1) # Wait for USB to become ready
led = Pin(5, Pin.OUT) 

led.value(1)
time.sleep(1)
led.value(0)
time.sleep(1)
led.value(1)
time.sleep(2)
led.value(0)
time.sleep(2)
led.value(1)
time.sleep(3)
led.value(0)
time.sleep(3)
led.value(1)
time.sleep(4)
led.value(0)
time.sleep(4)