import machine
import utime

# Define the GPIO pins for the traffic light LEDs
RED_LED_PIN = 0  # GP 0
YELLOW_LED_PIN = 2  # GP 2
GREEN_LED_PIN = 8  # GP 8

# Initialize the GPIO pins for the LEDs
red_led = machine.Pin(RED_LED_PIN, machine.Pin.OUT)
yellow_led = machine.Pin(YELLOW_LED_PIN, machine.Pin.OUT)
green_led = machine.Pin(GREEN_LED_PIN, machine.Pin.OUT)

# Function to turn on the specified LED and turn off the others
def turn_on_led(led_pin):
    red_led.value(led_pin == RED_LED_PIN)
    yellow_led.value(led_pin == YELLOW_LED_PIN)
    green_led.value(led_pin == GREEN_LED_PIN)

# Traffic light sequence
while True:
    # Red light
    turn_on_led(RED_LED_PIN)
    utime.sleep(2)  # Red light for 2 seconds

    # Red and yellow lights (transition)
    turn_on_led(YELLOW_LED_PIN)
    utime.sleep(1)  # Red and yellow lights for 1 seconds

    # Green light
    turn_on_led(GREEN_LED_PIN)
    utime.sleep(2)  # Green light for 2 seconds

    # Yellow light
    turn_on_led(YELLOW_LED_PIN)
    utime.sleep(1)  # Yellow light for 1 seconds