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      1 /*
      2  * Author: Jon Trulson <jtrulson (at) ics.com>
      3  * Copyright (c) 2015 Intel Corporation.
      4  *
      5  * Permission is hereby granted, free of charge, to any person obtaining
      6  * a copy of this software and associated documentation files (the
      7  * "Software"), to deal in the Software without restriction, including
      8  * without limitation the rights to use, copy, modify, merge, publish,
      9  * distribute, sublicense, and/or sell copies of the Software, and to
     10  * permit persons to whom the Software is furnished to do so, subject to
     11  * the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be
     14  * included in all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     23  */
     24 #pragma once
     25 
     26 #include <iostream>
     27 #include <string>
     28 #include <mraa/aio.h>
     29 
     30 // EZ series is volts/512
     31 #define MAXSONAREZ_RES  512
     32 
     33 namespace upm {
     34   /**
     35    * @brief MaxSonar-EZ Family of Ultrasonic Rangers library
     36    * @defgroup maxsonarez libupm-maxsonarez
     37    * @ingroup seeed analog sound
     38    */
     39 
     40   /**
     41    * @library maxsonarez
     42    * @sensor maxsonarez
     43    * @comname LV-MaxSonar-EZ Ultrasonic Ranger
     44    * @altname EZ1, EZ2, EZ3, EZ4
     45    * @type sound
     46    * @man sparkfun
     47    * @web https://www.sparkfun.com/products/8502
     48    * @con analog
     49    *
     50    * @brief API for the LV-MaxSonar-EZ Family of Ultrasonic Rangers
     51    *
     52    * Sensors of this family return an analog voltage corresponding to the
     53    * distance of an object from the sensor in inches. They have a
     54    * resolution of about 9.7 millivolts per inch with an analog reference voltage of 5.0 V. The
     55    * differences between various versions (EZ1, EZ2, etc.) are
     56    * related to the narrowness of the beam angle.
     57    *
     58    * This class supports these sensors with an analog input only.
     59    *
     60    * This driver was developed using an LV-MaxSonar-EZ3 ultrasonic ranger.
     61    *
     62    * @image html maxsonarez.jpg
     63    * <br><em>LV-MaxSonar-EZ Ultrasonic Ranger image provided by SparkFun* under
     64    * <a href=https://creativecommons.org/licenses/by-nc-sa/3.0/>
     65    * CC BY-NC-SA-3.0</a>.</em>
     66    *
     67    * @snippet maxsonarez.cxx Interesting
     68    */
     69 
     70   class MAXSONAREZ {
     71   public:
     72 
     73     /**
     74      * MAXSONAREZ constructor
     75      *
     76      * @param pin Analog pin to use
     77      * @param aref Analog reference voltage; default is 5.0 V
     78      */
     79     MAXSONAREZ(int pin, float aref=5.0);
     80 
     81     /**
     82      * MAXSONAREZ destructor
     83      */
     84     ~MAXSONAREZ();
     85 
     86     /**
     87      * Gets the distance to the object in inches
     88      *
     89      * @return Distance to the object in inches
     90      */
     91     int inches();
     92 
     93   private:
     94     mraa_aio_context m_aio;
     95     float m_aref;
     96     // ADC resolution
     97     int m_aRes;
     98     // computed volts per inch
     99     float m_vI;
    100   };
    101 }
    102 
    103 
    104