Arduino library for the Pololu Dual MC33926 Motor Driver Shield

Version: 4.0.0
Release date: 2018-04-11
www.pololu.com

Summary

This is a library for an Arduino-compatible controller that interfaces with the Pololu Dual MC33926 Motor Driver Shield. It makes it simple to drive two brushed, DC motors.

Getting started

Hardware

The Dual MC33926 Motor Driver Shield can be purchased on Pololu's website. Before continuing, careful reading of the product page as well as the motor shield user's guide is recommended.

Software

If you are using version 1.6.2 or later of the Arduino software (IDE), you can use the Library Manager to install this library:

1. In the Arduino IDE, open the "Sketch" menu, select "Include Library", then "Manage Libraries...".
2. Search for "DualMC33926MotorShield".
3. Click the DualMC33926MotorShield entry in the list.
4. Click "Install".

If this does not work, you can manually install the library:

1. Download the latest release archive from GitHub and decompress it.
2. Rename the folder "dual-mc33926-motor-shield-xxxx" to "DualMC33926MotorShield".
3. Drag the "DualMC33926MotorShield" folder into the "libraries" directory inside your Arduino sketchbook directory. You can view your sketchbook location by opening the "File" menu and selecting "Preferences" in the Arduino IDE. If there is not already a "libraries" folder in that location, you should make the folder yourself.
4. After installing the library, restart the Arduino IDE.

Example program

An example sketch is available that shows how to use the library. You can access it from the Arduino IDE by opening the "File" menu, selecting "Examples", and then selecting "DualMC33926MotorShield". If you cannot find these examples, the library was probably installed incorrectly and you should retry the installation instructions above.

Demo

The demo ramps motor 1 from stopped to full speed forward, ramps down to full speed reverse, and back to stopped. Then, it does the same with the other motor. Both motor's current readings are sent over serial and can be seen with the serial monitor. If a fault is detected, a message is sent over serial.

Documentation

• DualMC33926MotorShield()
  Default constructor, selects the default pins as connected by the motor shield.
• DualMC33926MotorShield(unsigned char M1DIR, unsigned char M1PWM, unsigned char M1FB, unsigned char M2DIR, unsigned char M2PWM, unsigned char M2FB, unsigned char nD2, unsigned char nSF)
  Alternate constructor for shield connections remapped by user. If M1PWM and M2PWM are remapped, it will try to use analogWrite instead of timer1.
• void init()
  Initialize pinModes and maybe timer1.
• void setM1Speed(int speed)
  Set speed and direction for motor 1. Speed should be between -400 and 400. 400 corresponds to motor current flowing from M1A to M1B. -400 corresponds to motor current flowing from M1B to M1A.
• void setM2Speed(int speed)
  Set speed and direction for motor 2. Speed should be between -400 and 400. 400 corresponds to motor current flowing from M2A to M2B. -400 corresponds to motor current flowing from M2B to M2A.
• void setSpeeds(int m1Speed, int m2Speed)
  Set speed and direction for motor 1 and 2.
• unsigned int getM1CurrentMilliamps()
  Returns current reading from motor 1 in milliamps.
• unsigned int getM2CurrentMilliamps()
  Returns current reading from motor 2 in milliamps.
• unsigned char getFault()
  Returns 1 if there is a motor driver fault, 0 if no fault.

Version history

• 4.0.0 (2018-04-11): Allow PWM remapping (use analogWrite if PWM pins remapped).
• 3.0.0 (2018-04-09): Remove M1PWM and M2PWM from pin-remapping constructor.
• 2.1.0 (2018-02-26): Added support for 20 kHz PWM on ATmega32U4.
• 2.0.0 (2016-08-19): Updated library to work with the Arduino Library Manager.
• 1.0.0 (2012-06-07): Original release.