1 /*
2  * Author: Jon Trulson <jtrulson@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 
ENC03R(int pin,float vref)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 
~ENC03R()47 ENC03R::~ENC03R()
48 {
49   mraa_aio_close(m_aio);
50 }
51 
value()52 unsigned int ENC03R::value()
53 {
54   return mraa_aio_read(m_aio);
55 }
56 
calibrate(unsigned int samples)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 
angularVelocity(unsigned int val)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