Controlling a Prop-2 with an Audio Track

[datbates]

Is there some way to control a prop-2 with audio?  I thought maybe there some way to
record serial on an audio track so that I can feed that into the prop 2 to give inputs
to my program.

I posted this question on the technical insanity list:

Does anyone know of a reasonably inexpensive way to convert the output of a
serial port to an audio track, and then back to serial again.  I am
trying to record a control track on a DVD.  This is basically a modem
I know, but modems unfortunately require all sorts of futzing around
to get them to start listening and to convert the phone signals to
audio.  Thanks!

and I got the answer:

Most micro controllers have a A/D converters built on and serial ports
embedded...

I know the basic stamp has this kind of functionality, but how do I do it?

Another responded:

I was thinking the exact same thing a couple o' years ago, and Jon from
EFX-TEK sugested using frequency-shift keying.

Maybe Jon can tell us a little about how this might be done?  I think it will
make the Prop-2 more useful for those of us with longer, audio
synchronized shows.

I am aware of the audio animator, but it seems quite crude using telephone tones.
I doubt it will be able to give me the performance or resolution I would like.

Thanks!!

[JonnyMac]

What you don't define is what you mean by "control" -- simple triggering from an audio track is quite doable.  A good friend of EFX-TEK, "Scary" Terry Simmons, has done this by embedding high-frequency (above normal hearing range) "beeps" into his audio track and using a tone-decoder IC to convert these to a signal that the Prop-1/Prop-2 can take as a trigger input.  Here's his write-up:

  http://www.scary-terry.com/more_stuff/tonedet/tonedet.htm

Be sure to use high-quality RC components if you decide to build this circuit.

[datbates]

I was really meaning like issuing commands in synch with an audio track...  Set channel 1 on,  Set servo 2 to position x, or run function x. 

[JonnyMac]

Now you're taking an ENORMOUS amount of work, and not trivial at that.  You might start with an off-the-shelf solution first: Vixen (www.vixenlights.com) sending command to the Prop-2.  We've been playing with this for servo control and digital output sync'd up with audio and it's a lot of fun.