import machine
import time

# Define the pins connected to the traffic lights
red_pin = machine.Pin(23, machine.Pin.OUT)
yellow_pin = machine.Pin(22, machine.Pin.OUT)
green_pin = machine.Pin(21, machine.Pin.OUT)

# Define the time intervals for each light
red_duration = 10
yellow_duration = 20
green_duration = 30

while True:
    red_pin.on()
    time.sleep(red_duration)
    red_pin.off()

    yellow_pin.on()
    time.sleep(yellow_duration)
    yellow_pin.off()

    green_pin.on()
    time.sleep(green_duration)
    green_pin.off()