This motor driver shield and its corresponding Arduino library make it easy to control a pair of bidirectional, brushed DC motors with an Arduino or compatible board, such as the A-Star 32U4 Prime. The board features a pair of Maxim’s MAX14870 H-bridge motor driver ICs, which allows it to operate from 4.5 V to 36 V and makes it well suited for driving higher-voltage motors like our 12V 20D gearmotors. The shield can deliver 1.7 A continuous per channel and tolerate peak currents up to 2.5 A per channel for a few seconds. The shield ships fully populated with its SMD components, including the MAX14870 drivers and a FET for reverse battery protection; header pins for interfacing with an Arduino and terminal blocks for connecting motors and power are included but are not soldered on.

The shield uses digital pins 4, 7, 8, 9, 10, and 12 for its control lines, though the control pin mappings can be customized if the defaults are not convenient. It should be compatible with any board that has a standard Arduino pin arrangement and the ability to generate PWM signals on pins 9 and 10. Compatible control boards include:

• A-Star 32U4 Prime
• Arduino Uno
• Arduino Leonardo
• Arduino Mega 2560

This shield is intended to provide a low-cost, basic motor driver option for Arduinos, so it is much smaller than typical Arduino shields and does not include pass-through, stackable headers.

FEATURES

• Two single-channel H-bridge motor drivers with shoot-through protection and internal free-wheeling diodes (can each drive one DC motor)
• Motor supply voltage: 4.5 V to 36 V
• Output current: 1.7 A continuous (2.5 A peak) per motor
• PWM operation up to 50 kHz (ultrasonic frequencies allow for quieter motor operation)
• Simple two-pin DIR/PWM interface (one pin controls direction and another controls speed)
• Shield can optionally power the Arduino base directly when motor supply voltage is suitable
• Shield has convenient location for adding a 3-pin voltage regulator to power the Arduino base in applications where the motor supply voltage is not suitable for powering the Arduino directly
• Arduino library makes it easy to get started using this board as a motor driver shield
• Arduino pin mappings can be customized (by cutting traces) if the default mappings are not convenient
• Reverse-voltage protection on motor power supply
• Under-voltage lockout
• Active-low fault output indicates over-current or over-temperature condition
• Surface-mount resistors can optionally be added to enable automatic current limiting