Step by Step motor, question on its possibilites

Hello everyone ,
in my need of using a Step by Step motor, I've some question about it's limits.

I've been using it for a while now, and i noticed that once you've began rotating the motor, it only stops when it arrives at the final position. Does anyone know how to stop/change direction of the motor while it's rotating ?
Indeed my angle of rotation is linked to the angle read by a accelerometer, and if the angle changes sign, the motor need to change sens as soon as possible, and not once it stopped.
Thank anyone for your help.
Nicolas R

Without seeing your program it is impossible to suggest an improvement.

...R
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