The code is linked in the YouTube video, but I have a link[1] for you.
The index.html[2] file is the web page source. It references the
processing.js[4] library and has all of the client-side code.
The processing-demo.js[3] file is the web server source and runs using
node.js and has all of the host-side code.
In the latest bonescript archive[5], I have included a JavaScript
terminal example[6] that runs on the BeagleBone at start-up and can be
visited on your local LAN via http://beaglebone.local/js_term.html.
This terminal window includes a Processing.JS canvas and a simple draw
routine I've used for playing around called graphDraw[7].
Making an oscilloscope on the BeagleBone from js_term.html is as
simple as typing the following lines into the browser:
var a = function(x) { graphDraw(x.value); };
var b = function() { analogRead(bone.P9_39, a); }
setInterval(b, 100);
The above will issue a message from the browser every 100ms to read an
analog value from pin P9-39 and to update the graph when given a
response. Function 'a' performs the graph update. Function 'b'
performs the analog read request providing function 'a' as a callback.
graphData uses Processing.JS and is part of the client.js script I've
put into the bone101 example application.
Hope this helps.
[1] https://gitorious.org/~Jadon/beagleboard-validation/jadons-education/trees/master/labs/processing-js
[2] https://gitorious.org/~Jadon/beagleboard-validation/jadons-education/blobs/master/labs/processing-js/index.html
[3] https://gitorious.org/~Jadon/beagleboard-validation/jadons-education/blobs/master/labs/processing-js/processingjs-demo.js
[4] https://gitorious.org/~Jadon/beagleboard-validation/jadons-education/blobs/master/labs/processing-js/processing.js
[5] https://github.com/jadonk/bonescript
[6] https://github.com/jadonk/bonescript/blob/master/bone101/js_term.html
[7] https://github.com/jadonk/bonescript/blob/master/bone101/client.js#L120