peripheral/libupm/examples/c++/mq6.cxx

/*
 * Author: Jon Trulson <jtrulson@ics.com>
 * Copyright (c) 2015 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <unistd.h>
#include <iostream>
#include "mq6.h"
#include <signal.h>
#include <stdlib.h>
#include <sys/time.h>

bool shouldRun = true;

using namespace std;

void
sig_handler(int signo)
{
  if (signo == SIGINT) 
    {
      shouldRun = false;
    }
}

//! [Interesting]
int main(int argc, char **argv)
{
  // Attach gas sensor to Analog A0
  upm::MQ6 *sensor = new upm::MQ6(0);
  signal(SIGINT, sig_handler);
  
  uint16_t buffer [128];

  thresholdContext ctx;
  ctx.averageReading = 0;
  ctx.runningAverage = 0;
  ctx.averagedOver   = 2;
  
  // Infinite loop, ends when script is cancelled
  // Repeatedly, take a sample every 2 microseconds;
  // find the average of 128 samples; and
  // print a running graph of asteriskss as averages
  while (shouldRun) 
    {
      int len = sensor->getSampledWindow (2, 128, buffer);
      if (len) {
        int thresh = sensor->findThreshold (&ctx, 30, buffer, len);
        sensor->printGraph(&ctx, 5);
        if (thresh) {
          // do something ....
        }
      }
    }
  
  cout << "Exiting" << endl;
  
  delete sensor;
  
  return 0;
}
//! [Interesting]