from machine import Pin, Timer
led = Pin("LED", Pin.OUT)
timer = Timer()
def blink(timer):
led.toggle()
timer.init(freq = 2.5, mode = Timer.PERIODIC, callback = blink)or
from machine import Pin
import time
led = Pin("LED", Pin.OUT)
if __name__ == "__main__":
while True:
led.toggle()
time.sleep(1)