import machine
import utime

led_red = machine.Pin(15, machine.Pin.OUT)
led_amber = machine.Pin(14, machine.Pin.OUT)
led_green = machine.Pin(13, machine.Pin.OUT)

while True:
    led_red.value(1) 
    utime.sleep(5) 
    led_amber.value(1) 
    utime.sleep(2) 
    led_red.value(0) 
    led_amber.value(0) 
    led_green.value(1)
    utime.sleep(5) 
    led_green.value(0) 
    led_amber.value(1) 
    utime.sleep(5) 
    led_amber.value(0)