// HW-130 Motor Shield - Basic DC motor control #define ENA 10 // PWM speed for M1/M2 #define IN1 8 #define IN2 9 #define ENB 5 // PWM speed for M3/M4 #define IN3 6 #define IN4 7

delay(1000);

According to various technical datasheets for this hardware revision: Adafruit Motor Shield