First commit

.gitignore

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+*.pyc
+*.sw*
+tests
+tests/*

README.md

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+HC-SR04 Ultrasonic Sensor on Raspberry Pi
+=========================================
+
+A simple module for calculating distance in centimeters, using an HC-SR04 sensor and a
+Raspberry Pi.
+
+
+Install
+=======
+
+    pip install hcsr04sensor
+
+Description
+===========
+The module does the following;
+
+* Returns an error corrected distance by using the median reading of a sorted
+  sample.  
+
+* Rounds the value to a specified decimal place.
+
+* Adjusts the reading based on temperature by adjusting the speed of sound.
+
+Usage
+=====
+
+See example scripts in https://github.com/alaudet/hcsr04sensor.git/examples

examples/depth.py

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+#!/usr/bin/python
+
+
+import hcsr04sensor.pihcsr04 as sensor
+
+
+def depth(hole_depth):
+    '''measure the distance in cm's and return a rounded float'''
+    trig_pin = 17
+    echo_pin = 27
+    rounded_to = 1
+    temperature = 20
+    value = sensor.Measurement(trig_pin, echo_pin, rounded_to, temperature)
+    distance = value.distance()
+    return hole_depth - distance
+
+if __name__ == "__main__":
+    hole_depth = 100
+    level = depth(float(hole_depth))
+    print "The water is {} centimeters deep".format(round(level, 1))

examples/distance.py

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+#!/usr/bin/python
+
+import hcsr04sensor.pihcsr04 as sensor
+
+
+def distance():
+    '''measure the distance in cm's and return a rounded float'''
+    trig_pin = 17
+    echo_pin = 27
+    rounded_to = 1
+    temperature = 20
+    value = sensor.Measurement(trig_pin, echo_pin, rounded_to, temperature)
+    return value.distance()
+
+if __name__ == "__main__":
+    distance = distance()
+    print "The measured distance is {} centimeters".format(distance)

hcsr04sensor/pihcsr04.py

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+import time
+import math
+import RPi.GPIO as GPIO
+
+
+class Measurement(object):
+    '''Create a distance measurement using an HC-SR04 Ultrasonic Sensor'''
+    def __init__(self, trig_pin, echo_pin, rounded_to, temperature):
+        self.trig_pin = trig_pin
+        self.echo_pin = echo_pin
+        self.rounded_to = rounded_to
+        self.temperature = temperature
+
+    def distance(self):
+        """Return the distance in cm of an object, accounting for 
+        temperature in Celcius."""
+        GPIO.setwarnings(False)
+        GPIO.setmode(GPIO.BCM)
+        speed_of_sound = 331.3 * math.sqrt((1+(self.temperature / 273.15)))*100
+        sample = []
+        for distance_reading in range(11):
+            GPIO.setup(self.trig_pin, GPIO.OUT)
+            GPIO.setup(self.echo_pin, GPIO.IN)
+            GPIO.output(self.trig_pin, GPIO.LOW)
+            time.sleep(0.3)
+            GPIO.output(self.trig_pin, True)
+            time.sleep(0.00001)
+            GPIO.output(self.trig_pin, False)
+            while GPIO.input(self.echo_pin) == 0:
+                sonar_signal_off = time.time()
+            while GPIO.input(self.echo_pin) == 1:
+                sonar_signal_on = time.time()
+            time_passed = sonar_signal_on - sonar_signal_off
+            distance_cm = time_passed * (speed_of_sound / 2)
+            sample.append(distance_cm)
+            GPIO.cleanup()
+        sorted_sample = sorted(sample)
+        sensor_distance = sorted_sample[5]
+        return round(sensor_distance, self.rounded_to)

setup.py

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+from setuptools import setup
+import os
+version = '0.0.1'
+
+
+setup(name='hcsr04sensor',
+      version=version,
+      description='Simple module to access HCSR04 sensor on RaspiPi',
+      long_description=open("./README.md", "r").read(),
+      classifiers=[
+          "Development Status :: 4 - Beta",
+          "Environment :: Console",
+          "Intended Audience :: End Users/Desktop",
+          "Natural Language :: English",
+          "Operating System :: POSIX :: Linux",
+          "Programming Language :: Python :: 2.7",
+          "Topic :: Home Automation",
+          "License :: OSI Approved :: MIT License",
+          ],
+      author='Al Audet',
+      author_email='alaudet@linuxnorth.org',
+      url='http://www.linuxnorth.org/',
+      download_url='https://github.com/alaudet/',
+      license='MIT License',
+      packages=['hcsr04sensor'],
+      install_requires=['RPi.GPIO']
+      )