I will be building a system with multiple servos, but the servos won't constantly be moving. For example, many of the servos will frequently move to a position then hold it for seconds at a time.

It would be nice to be able to send a control signal once, telling the servo to move to that position, then hold it, without having to constantly emit a PWM signal.

Do servo controller boards typically handle this? Can they take in a serial signal indicating position, then handle the constant transmission of the PWM to that server until a new signal is received? This would free up the primary processor to do other things. I'm very green on this so it's not clear to me whether this is a standard servo controller functionality or not.

 

Certainly there are devices that can do this. It's pretty easy for a microcontroller, pretty difficult any other way.

Like this:
http://www.pololu.com/catalog/product/207

 

I'm amazed nobody has designed and sold a "remembering servo" that works on some kind of simple SPI serial commands for position, then remembers its position until otherwise directed. This would make servos so much more usable in certain applications.

Or do these already exist?