maxsonarez: Initial implementation

The module supports the LV-MaxSonar EZ1, EZ2, EZ3 and EZ4 ultrasonic
range finders.  It was developed and tested on the EZ3 variant.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

examples/javascript/maxsonarez.js

@@ -0,0 +1,59 @@
+/*jslint node:true, vars:true, bitwise:true, unparam:true */
+/*jshint unused:true */
+/*
+* 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.
+*/
+
+// JavaScript example for the MaxSonar-EZ family of ultrasonic range finders
+
+// analog voltage, usually 3.3 or 5.0
+var MAXSONAREZ_AREF = 5.0;
+
+var MaxSonarEZ = require('jsupm_maxsonarez');
+
+// Instantiate a MaxSonar-EZ on analog pin A1, with an analog
+// reference voltage of MAXSONAREZ_AREF
+var mySonar = new MaxSonarEZ.MAXSONAREZ(1, MAXSONAREZ_AREF);
+
+// Every second, sample the sonar and output the distance to an
+// object in inches.
+
+// With the EZ3 version, the minimum and maximum ranges seemed to be
+// between 6 and 33 inches
+
+var myInterval = setInterval(function()
+{
+	console.log("AREF: " + MAXSONAREZ_AREF + 
+                    ", distance in inches: " + mySonar.inches());
+}, 1000);
+
+// Print message when exiting
+process.on('SIGINT', function()
+{
+	clearInterval(myInterval);
+	mySonar = null;
+	MaxSonarEZ.cleanUp();
+	MaxSonarEZ = null;
+	console.log("Exiting...");
+	process.exit(0);
+});