Hi,
I want to control a DC motor with a closed loop system to be nice and accurate.
So far I have controlled a stepper motor using a bunch of components so that all the arduino board needs to do is pulse on one line for one step and control direction on a second line.
I like this kind of system, where the arduino board is not bothered with thinking about the inside of the problem. It can just send instructions. It would be even better if I could send some serial instruction like 'turn to 120 degrees'.
I'm interested if anyone has any advice or recommendations for closed loop motor control??
As always, I want a good system for cheap

I notice on the Arduino site, there are plans for a motor control shield. Does anyone have any experience on building and using this shield? Does this shield deal with the logic of motor control or is that left for the Arduino board program to deal with??
Any advice would be great
Thanks /Jonathan