This interface defines a listener that is notified of the tachometer when the motor starts and stops rotating.
It doesn't matter if start/stop rotation is caused by Motor.forward() or Motor.rotateTo(), or if the rotation
is terminated by rotationTo() finishing naturally or by stop(). If the motor state changes directly from forward()
to backward(), then a stop() is called in between which results in a new rotationEnded() and rotationStarted() notification.
void rotationStarted(RegulatedMotor motor,
Called when the motor starts rotating.
void rotationStopped(RegulatedMotor motor,
Called when the motor stops rotating. This includes both Motor.stop() which locks the shaft, and
Motor.flt() in which the shaft floats freely after power is cut to the motor. Beware: In the second case, it's possible
the tachomoter reading will continue changing after notification.