odrive_ros
ROS driver for the ODrive motor driver
This is a basic pass at a ROS driver to operate the ODrive as a differential drive. 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 include adding a simulation mode so you can continue to use this driver in a simulation mode within gazebo.
Feedback, issues and pull requests welcome.
Usage
You will need the main ODrive Python tools installed.
To install:
git clone https://github.com/madcowswe/ODrive
cd ODrive/tools
sudo pip install monotonic # required for py < 3
# 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-xxx.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 .
If you want to use a bare 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.calibrate() # does a calibration
od.engage() # get ready to drive
od.drive(1000,1000) # drive axis0 and axis1
od.release() # done
You can now (as of v0.5) use this wrapper from within an odrivetool shell
. Once the shell has launched and connected to your ODrive, run the following, then you can use the commands as if in a bare Python interactive session above, and still get the help provided by odrivetool.
import odrive_interface
od = odrive_interface.ODriveInterfaceAPI(active_odrive=odrv0)
Acknowledgements
Thanks to the ODrive team for a great little bit of hardware and the active community support. Hope this helps!
Thanks to Simon Birrell for his tutorial on how to package a Python-based ROS package.