from machine import Pin
from time import sleep

# Define the pins for the LEDs
RED_LED_PIN = 18
YELLOW_LED_PIN = 17
GREEN_LED_PIN = 16

# Setup the LEDs as output
red_led = Pin(RED_LED_PIN, Pin.OUT)
yellow_led = Pin(YELLOW_LED_PIN, Pin.OUT)
green_led = Pin(GREEN_LED_PIN, Pin.OUT)

def traffic_light():
    while True:
        # Red light on for 5 seconds
        red_led.on()
        yellow_led.off()
        green_led.off()
        sleep(3)
    
        # Yellow light on for 2 seconds
        red_led.off()
        yellow_led.on()
        green_led.off()
        sleep(1)

        # Green light on for 5 seconds
        red_led.off()
        yellow_led.off()
        green_led.on()
        sleep(2)

# Start the traffic light simulation
traffic_light()