mq3: JavaScript example

Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Sarah Knepper <sarah.knepper@intel.com>

examples/javascript/gas/mq3.js

@@ -0,0 +1,60 @@
+/*jslint node:true, vars:true, bitwise:true, unparam:true */
+/*jshint unused:true */
+/*global */
+/*
+* Author: Zion Orent <zorent@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.
+*/
+
+var upmMQ3 = require("jsupm_gas");
+
+// Attach gas sensor to AIO0
+var myMQ3 = new upmMQ3.MQ3(0);
+
+var threshContext = new upmMQ3.thresholdContext;
+threshContext.averageReading = 0;
+threshContext.runningAverage = 0;
+threshContext.averagedOver = 2;
+
+// Infinite loop, ends when script is cancelled
+// Repeatedly, take a sample every 2 milliseconds;
+// find the average of 128 samples; and
+// print a running graph of the averages using a resolution of 5
+while(1)
+{
+    var buffer = new upmMQ3.uint16Array(128);
+    var len = myMQ3.getSampledWindow(2, 128, buffer);
+    if (len)
+    {
+        var thresh = myMQ3.findThreshold(threshContext, 30, buffer, len);
+        myMQ3.printGraph(threshContext, 5);
+        //if (thresh)
+        //    console.log("Threshold is " + thresh);
+    }
+}
+
+// Print message when exiting
+process.on('SIGINT', function()
+{
+	console.log("Exiting...");
+	process.exit(0);
+});