from machine import Pin, PWM
from utime import sleep, sleep_us, sleep_ms
from hcsr04 import HCSR04

sensor = HCSR04(trigger_pin=5, echo_pin=18)
led = Pin(14, Pin.OUT)
buzzer = PWM(Pin(19))

def play_buzzer(freq, duration_ms=500, duty_value=512):
    buzzer.freq(freq)
    buzzer.duty(duty_value)
    sleep_ms(duration_ms)
    buzzer.duty(0)

while True:
    distance = sensor.distance_cm()
    if distance is not None:
        print("Distance:", distance, "cm")
        if distance >= 70:
            led.on()
            play_buzzer(448)
        else:
            led.off()
            buzzer.duty(0)

    sleep(0.1)