thanks for the help guys,
by "live" i mean real-time, and not by uploading code to the arduino for every plan
and have it do whatever it has to and for another plan of movements I would have to upload again and so on..
and I don't mean by any primitive way of control from the PC,
I mean a more sophisticated one,
like i wouldn't want to have just a graphic potentiometer on the PC screen
and move the motor's shaft around by moving my mouse,
I would like to send an array of numbers to the arduino
to move the motor's shaft by them and if there is something wrong with the position,
to have the encoder send the data to the arduino that will send the data to the PC and display it
and send correction command back in the chain to the motor..
does that make sense? is it possible?
as for the servo motor,
i didn't buy it yet so i am not sure if i will need a 12V for the control wire, but i understand what you are saying,
and i was assuming i will need an additional psu..
Thanks a lot!!
Roy.