Instructions

These instructions shoe how to get joint positions into HAL. Example video: machinekit driven by ros joint states 2016 01 10 15 20

Prerequisits

Installation of:

• ROS

• Machinekit development setup

• https://github.com/cdsteinkuehler/ros_hal_tests

• a ROS publisher /joint_path_command to which the listener node from ros_hal_tests can subscribe to

• depending on the hardware you will need to use this machinekit branch (no support !!!) which uses pins instead of params for the mesa hardware stepgen. BEWARE only tested on a mesa 5i20 card. YMMV

Usage

1

install the component from ros_hal_tests with the command comp --install joint_stream.comp

2

Start HAL in a new terminal with halrun. A running HAL is needed for ../scripts/halfile.py to set up a configuration from python with the Machinekit Cython bindings.

bas@xw6600:~$ halrun
msgd:0 stopped
rtapi:0 stopped
halcmd:

now type start in terminal to start the RT threads (of which there are none ATM)

3

load the HAL configuration

cd {wherever it's located}/ros_hello_machinekit/scripts
python halfile.py

4

start whatever ROS robot you are running as long as there is a /joint_path_command topic to attach to

5

rosrun listener listener.py will listen to messages of type JointTrajectory and put those into the ringbuffer jointpos where the joint_stream component attaches to this ringbuffer here

6

optional, get the joint position in halscope (if you don’t have hardware)

halscope -i ros.halscope &

select joint_stream.joint.00.pos-cmd for the first channel set Run Mode to Roll and move your joints.