Adafruit Motor Shield V2.0 Manual page 5

Drive a DC Motor
You can drive 2 DC motor with this shield. Here I will show you how to drive a DC
motor.
You need to do some preparing first:
•
Set SEN_A and SEN_B, connect the left 2 pins together with a jumper.
•
Connect MB_EN together with a jumper, as we are no going use an external power.
•
Connect your DC motor to Chanel 0 (OUT1 and OUT2).
Then open motor_dc example in the library. Upload the code to Seeeduino V4.2.
// Demo function:The application method to drive the DC motor.
// Author:Loovee (luweicong@seeed.cc)
// 2016-3-11
#include "MotorDriver.h"
MotorDriver motor;
void setup()
{
// initialize
motor.begin();
}