from machine import Pin 
from utime import sleep 

led_red = Pin(22,Pin.OUT) 
led_verde=Pin(21,Pin.OUT) 
led_amarillo=Pin(20,Pin.OUT) 

while True: 
    led_red.on() 
    sleep(2) 
    led_red.off() 

    led_verde.on() 
    sleep(2) 
    led_verde.off() 

    led_amarillo.on() 
    sleep(1) 
    led_amarillo.off() 

    sleep(0)