from machine import Pin,PWM
from time import sleep,sleep_us


trigger =Pin (26,Pin.OUT)
echo=Pin(22,Pin.IN)
buzz=Pin(5,Pin.OUT)
def get_distance():
    trigger.on()
    sleep_us(10)
    trigger.off()
    duration =machine.time_pulse_us(echo,1,30000)
    distance =duration*0.0343/2
    return distance

while True:
    temp=get_distance()
    if temp<=50:
        print('obstacle head')
        buzz.on()
        sleep_us(1000)
        buzz.off()
    else:
        print('no obstacle found')
        buzz.off()
        sleep_us(1000)