[[Image(distVera.png, align=right, width=300px)]]
= Distance sensor (HC-SR04) =

== Software ==
You can download the Arduino sketch here:\\
http://code.mios.com/git_public/mios/arduino-sensor.git/tree/HEAD:/VeraArduino/Arduino/libraries/Vera/examples/DistanceSensor?js=1

Adjust the measure interval by updating SLEEP_TIME define at the top of the sketch file. 

This sensor requires you to upload the following device files to Vera as well.\\
http://code.mios.com/git_public/mios/arduino-sensor.git/tree/HEAD:/VeraArduino/Vera/distance?js=1\\
D_DistanceSensor1.xml\\
D_DistanceSensor1.json\\
S_DistanceSensor1.xml\\

== Wire things up ==
Follow the instructions in ConnectingRadioModule to connect radio module.

The HC-SR04 sends out short ultrasonic pulses and registers when the sound echo comes back. By knowing the speed of sound you can easily calculate the distance. 
To connect the HC-SR04 sensor to the Arduino board follow these instructions:\\
Connect VCC of the HC-SR04 sensor to +5V\\
Connect Echo to digital pin 5 of the Arduino board\\
Connect Trig to digital pin 6 of the Arduino board\\
Connect GND to Arduino ground\\

== Hardware - Purchase guide ==

To build this sensor you'll need one arduino + radio specified in the base kit found here:\\
http://code.mios.com/trac/mios_arduino-sensor/wiki/WikiStart#Buyingguide\\

With the following additional parts:\\
1x [[http://www.jdoqocy.com/click-7319170-10881559?url=http%3A%2F%2Fwww.aliexpress.com%2Fitem%2FFree-shipping-2pcs-Ultrasonic-Module-HC-SR04-Distance-Measuring-Transducer-Sensor-for-Arduino-Samples-Best-prices%2F690139020.html|HC-SR04 Distance Sensor]]\\

TOTAL SENSOR PRICE: $7.6 (arduino + radio) + $2.42 (HC-SR04) = '''$10'''

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