#!/usr/bin/python
# -*- coding: utf-8 -*-
# Author : www.modmypi.com
# Link: https://www.modmypi.com/blog/hc-sr04-ultrasonic-range-sensor-on-the-raspberry-pi

import time

import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BOARD)

TRIG = 36
ECHO = 32

print("Distance Measurement In Progress")

GPIO.setup(TRIG, GPIO.OUT)
GPIO.setup(ECHO, GPIO.IN)

GPIO.output(TRIG, False)
print("Waiting For Sensor To Settle")
time.sleep(2)

GPIO.output(TRIG, True)
time.sleep(0.00001)
GPIO.output(TRIG, False)

while GPIO.input(ECHO) == 0:
    pulse_start = time.time()

while GPIO.input(ECHO) == 1:
    pulse_end = time.time()

pulse_duration = pulse_end - pulse_start

distance = pulse_duration * 17150

distance = round(distance, 2)

print("Distance: {} cm".format(distance))

GPIO.cleanup()
