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 "mq303a.h"
30
31 using namespace upm;
32
MQ303A(int pin,int heaterPin)33 MQ303A::MQ303A(int pin, int heaterPin)
34 {
35 if ( !(m_aio = mraa_aio_init(pin)) )
36 {
37 throw std::invalid_argument(std::string(__FUNCTION__) +
38 ": mraa_aio_init() failed, invalid pin?");
39 return;
40 }
41
42 if ( !(m_gpio = mraa_gpio_init(heaterPin)) )
43 {
44 throw std::invalid_argument(std::string(__FUNCTION__) +
45 ": mraa_gpio_init() failed, invalid pin?");
46 return;
47 }
48 mraa_gpio_dir(m_gpio, MRAA_GPIO_OUT);
49 }
50
~MQ303A()51 MQ303A::~MQ303A()
52 {
53 heaterEnable(false);
54 mraa_aio_close(m_aio);
55 mraa_gpio_close(m_gpio);
56 }
57
value()58 int MQ303A::value()
59 {
60 return (1023 - mraa_aio_read(m_aio));
61 }
62
heaterEnable(bool enable)63 void MQ303A::heaterEnable(bool enable)
64 {
65 if (enable)
66 mraa_gpio_write(m_gpio, 0); // 0 turns on the heater
67 else
68 mraa_gpio_write(m_gpio, 1); // 1 turns off the heater
69 }
70