This module integrates a built-in 5V power supply. When you drive the voltage of 7V-35V, you can enable the onboard 5V logic power supply, when using the onboard 5V power supply, the interface of the + 5V power supply does not input voltage, but can lead to 5V voltage for external use 
when the ENA Enable IN1 IN2 control OUT1 OUT2 
when ENB is enabled IN3 IN4 controls OUT3 OUT4

★ Application Example 
1: Driving the stepper motor
drive Normal 4-wire 2-phase motor connection As shown in 
the figure, after 
the ENA ENB is enabled, the following timing is input from IN1 - IN4 to control the speed and direction of the stepper motor

2: Driving the DC motor
Since the module is a 2-way H-bridge drive, the two motors can be driven at the same time. 
After the ENA ENB is enabled, the 
PWM signal can be driven from the IN1 IN2 to drive the motor 1 speed and direction 
can be input PWM signal to drive the motor speed and direction 2 from IN3 IN4 respectively 
signal shown in FIG.