my9221: Add C++ and JS examples

These were tested on the Grove LED Bar.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Zion Orent <zorent@ics.com>
Signed-off-by: John Van Drasek <john.r.van.drasek@intel.com>

examples/javascript/my9221.js

@@ -0,0 +1,73 @@
+/*jslint node:true, vars:true, bitwise:true, unparam:true */
+/*jshint unused:true */
+/*
+* 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 LEDBar = require("jsupm_my9221");
+
+// Instantiate a MY9221, we use D2 for the data, and D3 for the
+// data clock.  This was tested with a Grove LED bar.
+var myLEDBar = new LEDBar.MY9221(2, 3);
+
+var directionBool = true;
+
+// A note on timing:
+//	In the C++ example, the system sleeps 10 times for 50 milliseconds
+//	between each LED lighting. After the LED has reached the last light
+//	of the cycle, the system sleeps again for 1 second.
+//	The sleeps are cumulative, so the system has slept for 1.5 seconds
+//	sum total for each cycle.
+//	setInterval and setTimeout make asynchronous function calls;
+//	they aren't cumulative.
+//	In order to approximate the behavior of the C++ example, we need
+//	to call each iteration 1.5 seconds apart instead of 1 second apart.
+var myInterval = setInterval(function()
+{
+	// start showing LED strip with just the first one lit
+	show_LED(1, directionBool);
+}, (1000 + (10*50)) );
+
+function show_LED(level, direction)
+{
+	// If it's less than 10
+	//	light up the LED now
+	//	call show_LED again in 50 ms
+	if (level <= 10)
+	{
+		myLEDBar.setBarLevel(level, directionBool);
+		setTimeout(show_LED, 50, ++level, directionBool);	
+	}
+	// Switch LED lighting directions between lighting cycles
+	else
+		directionBool = !directionBool;
+}
+
+// When exiting: clear LED strip lights, clear interval, print exit message
+process.on('SIGINT', function()
+{
+	myLEDBar.setBarLevel(0, true);
+	clearInterval(myInterval);
+	console.log("Exiting...");
+	process.exit(0);
+});