[GreenKeys] Something silly

[keelan at beefchicken.com]

I got to thinking recently... Web browsers have gained better audio 
support in recent times, and it should be possible to generate AFSK 
tones entirely in the browser.

And it is. I've put together a demo here:

http://beefchicken.com/rtty/

The interface isn't anything to write home about, this is just a quick 
wrapper for a clump of javascript code that makes the magic happen. A 
bit of random button mashing sound make the function of the poorly 
labeled buttons become apparent in short order. Basically, set up your 
mark/space frequencies and baud rate, and hit 'start audio'. If your 
browser works, you should hear the mark frequency. Poke the 'Encode' 
button and the AFSK will commence. This is all 'rendered' locally, if 
you load this page up it will continue to work even without an internet 
connection.

I've tested it successfully with Chrome and Safari. Firefox doesn't work 
(haven't bothered to figure out why yet), and I can't be bothered to 
test it with IE, because I'm 98% certain IE doesn't have support for the 
features I'm using here.

The source is available here:

https://github.com/naleek/rttyjs

I'm also working on a 'streaming' system that uses this code to generate 
the tones locally, based off of a live data stream, but I'm not sure 
it's worth the effort. It would mean a single 'radio station' could work 
with different baud rates/codes.

- Keelan
VE7NCR