from machine import Pin
from utime import sleep
  
ledRed = Pin(1, Pin.OUT)
ledYellow = Pin(5, Pin.OUT)
ledGreen = Pin(9, Pin.OUT)

while True:
  ledGreen.toggle()
  sleep(3)
  ledGreen.toggle()
  ledYellow.toggle()
  sleep(1)
  ledYellow.toggle()
  ledRed.toggle()
  sleep(3)
  ledRed.toggle()