Digital output

11-led_pulse_w_loop.py

from machine import Pin
import time

led = Pin('LED', Pin.OUT)

while True:
    led.value(1)
    time.sleep(.75)
    led.value(0)
    time.sleep(.25)

12-led_pulse_w_timer.py

from machine import Pin, Timer

led = Pin('LED', Pin.OUT)

timer = Timer()

def pulse(timer):
    led.toggle()

timer.init(freq=2, mode=Timer.PERIODIC, callback=pulse)