from machine import Pin,time_pulse_us,PWM
from time import sleep,sleep_us
trigg=Pin(3,Pin.OUT)
echo=Pin(2,Pin.IN)
led=Pin(15,Pin.OUT)
buzz=PWM(14)
buzz.freq(1000)
threshold=200
def get_dist():
    trigg.low()
    sleep_us(2)
    trigg.high()
    sleep_us(10)
    trigg.low()
    duration=time_pulse_us(echo,1)

    distance=(duration * 0.0343) /2

    return distance
while True:
    d=get_dist()
    print("Distance: ",d,"cm")
    if d < threshold:
        led.on()
    else:
        led.off()
        buzz.duty_u16(1)
        sleep(5)