I think that the motorshield and AFmotor.h are using the bluetooth Serial pins for one of the motors.
Try putting the BT software serial pins on two of the analog pins. They can be used as digital pins, and they are not used by AFMotor.h.
I think that the motorshield and AFmotor.h are using the bluetooth Serial pins for one of the motors.
Try putting the BT software serial pins on two of the analog pins. They can be used as digital pins, and they are not used by AFMotor.h.