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      1 /*
      2  * Author: Jon Trulson <jtrulson (at) ics.com>
      3  * Copyright (c) 2014 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 
     25 #include <iostream>
     26 #include <string>
     27 #include <stdexcept>
     28 
     29 #include "enc03r.h"
     30 
     31 using namespace upm;
     32 using namespace std;
     33 
     34 ENC03R::ENC03R(int pin, float vref)
     35 {
     36   if ( !(m_aio = mraa_aio_init(pin)) )
     37     {
     38       throw std::invalid_argument(std::string(__FUNCTION__) +
     39                                   ": mraa_aio_init() failed, invalid pin?");
     40       return;
     41     }
     42 
     43   m_vref = vref;
     44   m_calibrationValue = 0;
     45 }
     46 
     47 ENC03R::~ENC03R()
     48 {
     49   mraa_aio_close(m_aio);
     50 }
     51 
     52 unsigned int ENC03R::value()
     53 {
     54   return mraa_aio_read(m_aio);
     55 }
     56 
     57 void ENC03R::calibrate(unsigned int samples)
     58 {
     59   unsigned int val;
     60   float total = 0.0;
     61 
     62   for (int i=0; i<samples; i++)
     63     {
     64       val = mraa_aio_read(m_aio);
     65       total += (float)val;
     66       usleep(2000);
     67     }
     68 
     69   m_calibrationValue = total / (float)samples;
     70 }
     71 
     72 double ENC03R::angularVelocity(unsigned int val)
     73 {
     74   // from seeed studio example
     75   //return (((double)(val-m_calibrationValue)*(m_vref*1000.0))/1023.0/0.67);
     76   return (((double)(val-m_calibrationValue)*(m_vref*1000.0))/685.41);
     77 }
     78