1 /*
2 * Author: Jon Trulson <jtrulson@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
25 #include <iostream>
26 #include <string>
27 #include <stdexcept>
28
29 #include "maxsonarez.h"
30
31 using namespace std;
32 using namespace upm;
33
MAXSONAREZ(int pin,float aref)34 MAXSONAREZ::MAXSONAREZ(int pin, float aref)
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_aRes = (1 << mraa_aio_get_bit(m_aio));
44 m_aref = aref;
45
46 // volt's per inch of this sensor
47 m_vI = (m_aref / MAXSONAREZ_RES);
48 }
49
~MAXSONAREZ()50 MAXSONAREZ::~MAXSONAREZ()
51 {
52 mraa_aio_close(m_aio);
53 }
54
inches()55 int MAXSONAREZ::inches()
56 {
57 int val = mraa_aio_read(m_aio);
58 float volts = float(val) * (m_aref / m_aRes);
59
60 return int(volts / m_vI);
61 }
62