Super simple computer control-Help

Thread Starter


Joined May 4, 2007
Hi everyone,
Im new here & also new to electronics.
I had a little idea of how to control the rotation of my motorized webcam (instead of buying a ready one) because I can then use the same method with other things.
I know what I want but I don't know how!.

The idea is pretty simple:
With actionscript in a flash movie, I can control the PC volume ammount on each channel (right & left). So throught the audio output, I want to connect a circuit that triggers the current (9V or 24V) depending of this volume ammount and channel.

If I play a continuous sound (beep) on the right channel, the motor will turn right; same with left channel.
It will be better if it works depending of the volume not just the sound being played.
Volume = 20% -> action1
Volume = 60% -> action 2
And so on on every channel.

I apologize if I'm asking too much, but is that possible to get help with a circuit scheme for that?.
I can provide the sound control flash movie at least :)

Thank you very much in advance.


Joined May 16, 2005
Can it be done? You bet!

Will it be simple? Depends on the definition of "simple" in this context...

You'll need a gizmo called a "comparator." If you want different actions from different volumes, you can use more than one comparator to make a "multiple aperture window discriminator." (See page 3, figure TL/H/7057-20 of this link.) You can also use multiples of a gizmo called a "filter" to control different outcomes by changing the tone/pitch of your signal.

Thread Starter


Joined May 4, 2007
Thank you for replying so quickly and for you suggestions.
I'll be ultimately thankful if you or somebody can provide a scheme I or someone else can use to build it, that's my final goal.
Thank you again.