odrive_ros

ROS driver for the ODrive motor driver

This is a basic first pass at a ROS driver. It's Python-based, so not super-fast, but it'll get you started. Maybe in time this will have an optimised C++ version, but I woudn't count on it anytime soon. ;)

Future plans do include:

• pull encoder parameter back from ODrive rather than specifying it manually
• publishing odometry back to ROS

Feedback, issues and pull requests welcome.

Usage

As of September 7, 2018 the main ODrive repository doesn't support Python 2.7, so you will need to ensure the version you install has my compatibility patch. Said patch is also is a bit rough around the edges, you will need to use the odrivetool for configuration according to the ODrive setup docs with python2 odrivetool instead of running it directly.

To install:

git clone https://github.com/neomanic/ODrive -b py27compat
cd ODrive/tools
sudo pip install monotonic

# sudo python setup.py install # doesn't work due to weird setup process, so do the following:
python setup.py sdist
sudo pip install dist/odrive-0.4.2.dev0.tar.gz

then rosrun odrive_ros odrive_node will get you on your way.

There is a sample launch file showing the use of the wheelbase, tyre circumference, and encoder count parameters too, try roslaunch odrive_ros odrive.launch or copy it into your own package and edit the values to correspond to your particular setup.

If you want to test out the driver separate from ROS, you can also install as a regular Python package.

roscd odrive_ros
sudo pip install -e .

Fire up a Python shell. See below for the import which exposes the ODrive with setup and drive functions. You can use either ODriveInterfaceAPI (uses USB) or ODriveInterfaceSerial (requires the /dev/ttyUSBx corresponding to the ODrive as parameter, but not tested recently).

from odrive_ros import odrive_interface
od = odrive_interface.ODriveInterfaceAPI()
od.connect()
od.setup()          # does a calibration
od.engage()         # get ready to drive
od.drive(1000,1000) # drive axis0 and axis1
od.release()        # done

Acknowledgements

Thanks to the ODrive team for a great little bit of hardware and the active community support. Hope this helps!

• ODrive homepage
• ODrive getting started
• ODrive main repo

Thanks to Simon Birrell for his tutorial on how to package a Python-based ROS package.