Dual Motor Driver Module board H-bridge DC MOSFET IRF3205 3-36V 10A

Nooobie with a MEGA, and I have a Dual Motor Driver Module board H-bridge DC MOSFET IRF3205 3-36V 10A, found here: http://www.ebay.com/itm/New-Dual-Motor-Driver-Module-board-H-bridge-DC-MOSFET-IRF3205-3-36V-10A-Peak-30A-/111401192055?pt=LH_DefaultDomain_0&hash=item19f0074a77

I am building a 2 brushed motor autonomous robot with a ping sensor.

I am using a Mac computer.

Ping sensor works, and I have it mounted on a stepper motor, and it does swing back and forth. Serial screen indicates changes with distance change.

So I have this board, and I have tested it and it works when given a PWM signal. Problem is, it does NOT have a M1F and a M1B (Motor 1 Forward, Motor 1 Backward) signal pins, or enable, as it were...

The board has DIR 1, DIR 2, and PWM 1, PWM 2. Just four pins, not including logic power.

PWM 1 gives an output to 1 Motor, when DIR 1 is low it is one DIRection, and when high it is the other direction. I tested it with a PWM signal, works as advertised.

I can not find any sketches that use the DIR high/low command to change directions.

Can anyone URL me?

here are the motor connections to the board: https://www.rc89.com/image/data/AROBOTICS/parts/RC8900214415005.jpg