#
# Traffic Light
#
import board
import digitalio
import time

# set up LED's and Direction

red = digitalio.DigitalInOut(board.GP12)
red.direction = digitalio.Direction.OUTPUT

yellow = digitalio.DigitalInOut(board.GP11)
yellow.direction = digitalio.Direction.OUTPUT

green = digitalio.DigitalInOut(board.GP10)
green.direction = digitalio.Direction.OUTPUT

# main loop
while True:
    # Switch from red light to green light then wait
    red.value = False
    green.value = True
    time.sleep(3)
    # Switch from green light to yellow light then wait a short time
    green.value = False
    yellow.value = True
    time.sleep(1)
    # Switch from the yellow light to the red light then wait 
    yellow.value = False
    red.value = True
    time.sleep(3)