learm_ros2

A collection of ROS 2 packages for controlling the Hiwonder LeArm.

Requirements

$ sudo apt-get install libusb-1.0-0-dev libudev-dev
$ pip install --upgrade setuptools
$ pip install hidapi
$ pip install xarm # see notes below

I ran into issues with the xarm package published on pip (specifically, my arm has servo values from 500-2500 instead of the 0-1000 that the package expects). If these issues apply to you as well, install my forked version:

$ pip uninstall xarm
$ pip install git+https://github.com/andrewda/xarmservocontroller.git#subdirectory=Python

Additionally, if you encounter errors while trying to connect to the arm, try adding the following udev rule to /etc/udev/rules.d/99-xarm.rules or similar:

SUBSYSTEM=="usb", ATTR{idVendor}=="0483", ATTR{idProduct}=="5750", MODE="0660", GROUP="plugdev"

Then reload the rules with:

$ sudo udevadm control --reload-rules && udevadm trigger

This rule will allow users in the plugdev group to access the arm controller.

Packages

Name	Description
learm_ros2	A simple follower that commands arm servo positions from joint states published on the joint_states topic.
learm_ros2_description	LeArm description files, including arm meshes and URDF files.
learm_ros2_moveit_config	MoveIt config files (WIP).

Running

Make sure that the LeArm is plugged into a power source, turned on, and connected over USB. Then start the follower:

$ ros2 launch learm_ros2 follower.launch.py

Next, if you want to manually control the arm for testing, start RViz and the joint publisher:

$ ros2 launch learm_ros2 run.launch.py