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      1 /*jslint node:true, vars:true, bitwise:true, unparam:true */
      2 /*jshint unused:true */
      3 /*
      4  * Author: Jon Trulson <jtrulson (at) ics.com>
      5  * Copyright (c) 2015 Intel Corporation.
      6  *
      7  * Permission is hereby granted, free of charge, to any person obtaining
      8  * a copy of this software and associated documentation files (the
      9  * "Software"), to deal in the Software without restriction, including
     10  * without limitation the rights to use, copy, modify, merge, publish,
     11  * distribute, sublicense, and/or sell copies of the Software, and to
     12  * permit persons to whom the Software is furnished to do so, subject to
     13  * the following conditions:
     14  *
     15  * The above copyright notice and this permission notice shall be
     16  * included in all copies or substantial portions of the Software.
     17  *
     18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     19  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     21  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     22  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     23  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     24  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     25  */
     26 
     27 var upmGAS = require("jsupm_gas");
     28 
     29 // Attach gas sensor to Analog A0
     30 var sensor = new upmGAS.MQ7(0);
     31 
     32 var threshContext = new upmGAS.thresholdContext;
     33 threshContext.averageReading = 0;
     34 threshContext.runningAverage = 0;
     35 threshContext.averagedOver = 2;
     36 
     37 // Infinite loop, ends when script is cancelled
     38 // Repeatedly, take a sample every 2 microseconds;
     39 // find the average of 128 samples; and
     40 // print a running graph of asteriskss as averages
     41 
     42 while(1)
     43 {
     44     var buffer = new upmGAS.uint16Array(128);
     45     var len = sensor.getSampledWindow(2, 128, buffer);
     46     if (len)
     47     {
     48         var thresh = sensor.findThreshold(threshContext, 30, buffer, len);
     49         sensor.printGraph(threshContext, 5);
     50         //if (thresh)
     51         //    console.log("Threshold is " + thresh);
     52     }
     53 }
     54 
     55 // Print message when exiting
     56 process.on('SIGINT', function()
     57 {
     58 	console.log("Exiting...");
     59 	process.exit(0);
     60 });
     61