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 <unistd.h>
26 #include <iostream>
27 #include "mq4.h"
28 #include <signal.h>
29 #include <stdlib.h>
30 #include <sys/time.h>
31 
32 bool shouldRun = true;
33 
34 using namespace std;
35 
36 void
sig_handler(int signo)37 sig_handler(int signo)
38 {
39   if (signo == SIGINT)
40     {
41       shouldRun = false;
42     }
43 }
44 
45 //! [Interesting]
main(int argc,char ** argv)46 int main(int argc, char **argv)
47 {
48   // Attach gas sensor to Analog A0
49   upm::MQ4 *sensor = new upm::MQ4(0);
50   signal(SIGINT, sig_handler);
51 
52   uint16_t buffer [128];
53 
54   thresholdContext ctx;
55   ctx.averageReading = 0;
56   ctx.runningAverage = 0;
57   ctx.averagedOver   = 2;
58 
59   // Infinite loop, ends when script is cancelled
60   // Repeatedly, take a sample every 2 microseconds;
61   // find the average of 128 samples; and
62   // print a running graph of asteriskss as averages
63   while (shouldRun)
64     {
65       int len = sensor->getSampledWindow (2, 128, buffer);
66       if (len) {
67         int thresh = sensor->findThreshold (&ctx, 30, buffer, len);
68         sensor->printGraph(&ctx, 5);
69         if (thresh) {
70           // do something ....
71         }
72       }
73     }
74 
75   cout << "Exiting" << endl;
76 
77   delete sensor;
78 
79   return 0;
80 }
81 //! [Interesting]
82