User Manual

Warning: When powering the Arduino from the motor shield, you must never connect a

different power supply to the Arduino’s VIN pin or plug a power supply into the Arduino’s

power jack, as doing so will create a short between the shield’s power supply and the

Arduino’s power supply that could permanently damage both the Arduino and the motor

shield. In this case, it is also important that your shield power supply is an acceptable voltage

for your Arduino, so the full shield operating voltage range of 5.5 – 24 V probably will not be

available. For example, the recommended operating voltage of the Arduino Uno is 7 – 12 V.

Note that the shorting block just routes the motor power to the Arduino VIN pin, so plugging

in USB with this shorting block in place is just like plugging in USB with the Arduino powered

from its power jack. On standard Arduinos we recommend against plugging a powered

Arduino into USB (see this forum post [https://forum.pololu.com/t/pololu-arduino-hardware-bug/

2461/7] for more information), but on some Arduino-compatible boards such as the A-Stars

[https://www.pololu.com/category/165/a-star-32u4-prime], this is completely safe.

Motor Connections and Considerations

This motor driver shield has two motor channels, M1 and M2, each of which can be used to

independently control a bidirectional brushed DC motor. Each motor channel is comprised of a pair of

pins—MxA and MxB—that connect to the two terminals of a DC motor and can deliver a continuous

12 A (30 A peak).

Note: It is also possible to connect a single brushed DC motor to both motor channels

simultaneously to deliver nearly twice the current as is available from a channel by itself.

See Section 7 for more information.

Each VNH5019 motor driver IC has a maximum continuous current rating of 30 A. However, the chips

by themselves will overheat at lower currents. In our tests on a sample unit, we were able to deliver

30 A for a few milliseconds, 20 A for several seconds, 15 A for over a minute, and 12 A for around

five minutes. At 6 A, the chip just barely gets noticeably warm to the touch. The actual current you can

deliver will depend on how well you can keep the motor driver cool. The shield’s printed circuit board

is designed to draw heat out of the motor driver chips, but performance can be improved by adding a

heat sink.

This product can get hot enough to burn you long before the chip overheats. Take care

when handling this product and other components connected to it.

3. Getting Started with an Arduino Page 14 of 35