WiFly + Motor Shield

Projects Networking, Protocols, and Devices
2 
int pwm_b = 11;  //PWM control for motor outputs 3 and 4 is on digital pin 11
int dir_a = 12;  //direction control for motor outputs 1 and 2 is on digital pin 12
int dir_b = 13;

You can NOT connect the motors to the SPI pins.