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