from machine import Pin
from utime import sleep

r = Pin(13, Pin.OUT)
y = Pin(12, Pin.OUT)
g = Pin(11, Pin.OUT)

while True:
    r.on()
    sleep(15)
    r.off()

    y.on()
    sleep(2)
    y.off()

    g.on()
    sleep(5)
    g.off()