This user’s guide focuses on the latest version (ash02b) of the Pololu dual VNH5019 motor driver shield, but most of the information also applies to the earlier ash02a version. See Section 8 for details about the differences between board revisions.
The Pololu dual VNH5019 motor driver shield for Arduino and its corresponding Arduino library make it easy to control two bidirectional, high-power DC motors with an Arduino or Arduino clone. The board features a pair of robust VNH5019 motor drivers from ST, which operate from 5.5 to 24 V and can deliver a continuous 12 A (30 A peak) per channel, and incorporates most of the components of the typical application diagram on page 14 of the VNH5019 datasheet (629k pdf), including pull-up and protection resistors and FETs for reverse battery protection. It ships fully populated with its SMD components, including the two VNH5019 ICs, as shown in the picture to the right; stackable Arduino headers and terminal blocks for connecting motors and motor power are included but are not soldered in.
This versatile motor driver is intended for a wide range of users, from beginners who just want a plug-and-play motor control solution for their Arduinos (and are okay with a little soldering) to experts who want to directly interface with ST’s great motor driver ICs. The Arduino pin mappings can all be customized if the defaults are not convenient, and the VNH5019 control lines are broken out along the left side of the board, providing a convenient interface point for other microcontroller boards. This versatility, along with an option to power the Arduino directly from the shield, sets this board apart from similar competing motor shields.