from machine import Pin
from utime import sleep

sleep(0.01) # Wait for USB to connect

red = Pin(5, Pin.OUT)
yellow = Pin(12, Pin.OUT)
green = Pin(28, Pin.OUT)
while True:
    red.toggle()
    sleep(5)
    red.toggle()
    yellow.toggle()
    sleep(5)
    yellow.toggle()
    green.toggle()
    sleep(5)
    green.toggle()