Datasheet

// On the top shield, connect two steppers, each with 200 steps

Adafruit_StepperMotor *myStepper2 = AFMStop.getStepper(200, 1);

Adafruit_StepperMotor *myStepper3 = AFMStop.getStepper(200, 2);

// On the bottom shield connect a stepper to port M3/M4 with 200 steps

Adafruit_StepperMotor *myStepper1 = AFMSbot.getStepper(200, 2);

// And a DC Motor to port M1

Adafruit_DCMotor *myMotor1 = AFMSbot.getMotor(1);

You can request a stepper or DC motor from any port, just be sure to use the right AFMS controller object when you

call getMotor or getStepper!

Then, both shields must have begin called, before you use the motors connected

AFMSbot.begin(); // Start the bottom shield

AFMStop.begin(); // Start the top shield

You can try out this code for yourself by setting up two shields and running the File->Examples-

>Adafruit_MotorShield->StackingTest example