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      1 /*jslint node:true, vars:true, bitwise:true, unparam:true */
      2 /*jshint unused:true */
      3 /*global */
      4 /*
      5 * Author: Zion Orent <zorent (at) ics.com>
      6 * Copyright (c) 2014 Intel Corporation.
      7 *
      8 * Permission is hereby granted, free of charge, to any person obtaining
      9 * a copy of this software and associated documentation files (the
     10 * "Software"), to deal in the Software without restriction, including
     11 * without limitation the rights to use, copy, modify, merge, publish,
     12 * distribute, sublicense, and/or sell copies of the Software, and to
     13 * permit persons to whom the Software is furnished to do so, subject to
     14 * the following conditions:
     15 *
     16 * The above copyright notice and this permission notice shall be
     17 * included in all copies or substantial portions of the Software.
     18 *
     19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     23 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     24 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     25 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     26 */
     27 
     28 var upmMicrophone = require("jsupm_mic");
     29 
     30 // Attach microphone to analog port A0
     31 var myMic = new upmMicrophone.Microphone(0);
     32 
     33 var threshContext = new upmMicrophone.thresholdContext;
     34 threshContext.averageReading = 0;
     35 threshContext.runningAverage = 0;
     36 threshContext.averagedOver = 2;
     37 
     38 var is_running = false;
     39 // Infinite loop, ends when script is cancelled
     40 // Repeatedly, take a sample every 2 microseconds;
     41 // find the average of 128 samples; and
     42 // print a running graph of the averages
     43 while(1)
     44 {
     45     var buffer = new upmMicrophone.uint16Array(128);
     46     var len = myMic.getSampledWindow(2, 128, buffer);
     47     if (len)
     48     {
     49         var thresh = myMic.findThreshold(threshContext, 30, buffer, len);
     50         myMic.printGraph(threshContext);
     51         if (thresh)
     52             console.log("Threshold is " + thresh);
     53     }
     54 }
     55 
     56 // Print message when exiting
     57 process.on('SIGINT', function()
     58 {
     59 	console.log("Exiting...");
     60 	process.exit(0);
     61 });
     62