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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 <unistd.h>
26 #include <iostream>
27 #include <signal.h>
28 #include "mq303a.h"
29 
30 using namespace std;
31 
32 int shouldRun = true;
33 
sig_handler(int signo)34 void sig_handler(int signo)
35 {
36   if (signo == SIGINT)
37     shouldRun = false;
38 }
39 
main()40 int main ()
41 {
42   signal(SIGINT, sig_handler);
43 
44 //! [Interesting]
45   // Instantiate an mq303a sensor on analog pin A0
46 
47   // This device uses a heater powered from an analog I/O pin.
48   // If using A0 as the data pin, then you need to use A1, as the heater
49   // pin (if using a grove mq303a).  For A1, we can use the D15 gpio,
50   // setup as an output, and drive it low to power the heater.
51 
52   upm::MQ303A *mq303a = new upm::MQ303A(0, 15);
53 
54   cout << "Enabling heater and waiting 2 minutes for warmup." << endl;
55   mq303a->heaterEnable(true);
56   sleep(120);
57 
58   cout << "This sensor may need to warm until the value drops below about 450."
59        << endl;
60 
61   // Print the detected alcohol value every second
62   while (shouldRun)
63     {
64       int val = mq303a->value();
65 
66       cout << "Alcohol detected (higher means stronger alcohol): "
67            << val << endl;
68 
69       sleep(1);
70     }
71 //! [Interesting]
72 
73   cout << "Exiting" << endl;
74   mq303a->heaterEnable(false);
75 
76   delete mq303a;
77   return 0;
78 }
79