dragosbratu / dual-g2-high-power-motor-shield

Arduino library for the Pololu Dual G2 High Power Motor Driver Shields

Arduino library for the Pololu Dual G2 High Power Motor Driver Shields

Version: 2.0.0
Release Date: 2018-04-11
www.pololu.com

Summary

This is a library for the Arduino IDE that interfaces with the Pololu Dual G2 High Power Motor Driver Shield 18v18, Dual G2 High Power Motor Driver Shield 24v14, Dual G2 High Power Motor Driver Shield 18v22, and Dual G2 High Power Motor Driver Shield 24v18. It makes it simple to drive two brushed, DC motors.

Supported platforms

This library is designed to work with the Arduino IDE versions 1.8.x or later; we have not tested it with earlier versions. This library should support any Arduino-compatible board, including the Pololu A-Star 32U4 controllers.

Getting started

Hardware

The Dual G2 High Power Motor Driver Shields can be purchased from Pololu's website. Before continuing, careful reading of the product page as well as the product user's guide is recommended.

Software

If you are using version 1.8.5 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 "DualG2HighPowerMotorShield".
3. Click the DualG2HighPowerMotorShield 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-g2-high-power-motor-shield-xxxx" to "DualG2HighPowerMotorShield".
3. Drag the "DualG2HighPowerMotorShield" 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

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 "DualG2HighPowerMotorShield". If you cannot find these examples, the library was probably installed incorrectly and you should retry the installation instructions above.

Demo

The demo enables the drivers and 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. After motor 2 is stopped, sleep mode is entered for 500 ms before the demo enables the drivers again. Current readings for each motor are sent over serial and can be seen with the serial monitor. If a fault is detected, a message is sent over serial.

Documentation

This library defines a DualG2HighPowerMotorShield base class that implements commands common to all versions of the Dual G2 High Power Motor Driver Shields. Four derived classes,DualG2HighPowerMotorShield24v14, DualG2HighPowerMotorShield18v18, DualG2HighPowerMotorShield24v18, and DualG2HighPowerMotorShield18v22, handle commands specific to each version.

Library Reference

DualG2HighPowerMotorShield

• DualG2HighPowerMotorShield()
  Default constructor, selects the default pins as connected by the motor shield.
• DualG2HighPowerMotorShield(unsigned char M1nSLEEP, unsigned char M1DIR, unsigned char M1PWM, unsigned char M1nFAULT, unsigned char M1CS, unsigned char M2nSLEEP, unsigned char M2DIR, unsigned char M2PWM, unsigned char M2nFAULT, unsigned char M2CS)
  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 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. 0 corresponds to full coast.
• 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. 0 corresponds to full coast.
• void setSpeeds(int m1Speed, int m2Speed)
  Set speed and direction for motor 1 and 2.
• unsigned char getM1Fault()
  Returns 1 if there is a fault on motor driver 1, 0 if no fault.
• unsigned char getM2Fault()
  Returns 1 if there is a fault on motor driver 2, 0 if no fault.
• void flipM1(bool flip)
  Flip the direction meaning of the speed passed to the setSpeeds function for motor 1. The default direction corresponds to flipM1(false) having been called.
• void flipM2(bool flip)
  Flip the direction meaning of the speed passed to the setSpeeds function for motor 2. The default direction corresponds to flipM2(false) having been called.
• void enableM1Driver()
  Enables the MOSFET driver for motor 1.
• void enableM2Driver()
  Enables the MOSFET driver for motor 2.
• void enableDrivers()
  Enables the MOSFET drivers for motor 1 and motor 2.
• void disableM1Driver()
  Puts the MOSFET driver for motor 1 into low-power sleep mode.
• void disableM2Driver()
  Puts the MOSFET driver for motor 2 into low-power sleep mode.
• void disableDrivers()
  Puts the MOSFET drivers for motor 1 and 2 into low-power sleep mode.
• unsigned int getM1CurrentReading()
  Returns current reading from motor 1
• unsigned int getM2CurrentReading()
  Returns current reading from motor 2
• void calibrateM1CurrentOffset()
  Records the voltage offset of the current reading from motor 1 when speed is 0.
• void calibrateM2CurrentOffset()
  Records the voltage offset of the current reading from motor 2 when speed is 0.
• void calibrateCurrentOffsets()
  Records the voltage offsets of the current readings from motor 1 and 2 when speeds are 0.
• unsigned int getM1CurrentMilliamps(int gain)
  Returns current reading for motor 1 in milliamps. Gain (mV/A) can be specified for a specific version of the shield.
• unsigned int getM2CurrentMilliamps(int gain)
  Returns current reading for motor 2 in milliamps. Gain (mV/A) can be specified for a specific version of the shield.

DualG2HighPowerMotorShield24v14, DualG2HighPowerMotorShield18v18, DualG2HighPowerMotorShield24v18, DualG2HighPowerMotorShield18v22

• unsigned int getM1CurrentMilliamps()
  Returns current reading for motor 1 in milliamps.
• unsigned int getM2CurrentMilliamps()
  Returns current reading for motor 2 in milliamps.

Current readings

The current readings returned by getM1CurrentMilliamps and getM2CurrentMilliamps will be noisy and unreliable if you are using a PWM frequency below about 5 kHz. We expect these readings to work fine if you are using a board based on the ATmega168, ATmega328P, or ATmega32U4, since this library uses 20 kHz hardware PWM on those boards.

On other boards, this library uses analogWrite to generate PWM signals, which usually means that the PWM frequency will be too low to get reliable current measurements.

Version history

• 2.0.0 (2018-04-11): Allow PWM remapping (use analogWrite if PWM pins remapped).
• 1.0.0 (2017-11-09): Original release.