#!/usr/bin/python3
# Datei ultraschall.py
import time
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)
trig = 5  # GPIO-Pin-Nummern
echo = 17
GPIO.setup(echo, GPIO.IN)
GPIO.setup(trig, GPIO.OUT)

while True:
    GPIO.output(trig, True)
    time.sleep(0.00001) # 10 Mikrosekunden
    GPIO.output(trig, False)

    while GPIO.input(echo) == 0:
        pass
    start = time.time()   
    while GPIO.input(echo) == 1:
        pass
    ende = time.time()
    entfernung = ((ende - start) * 34300) / 2
    print("Entfernung:", entfernung, "cm")
    time.sleep(0.5)