ROS cheat sheet

Basic codes

source ~/catkin_ws/devel/setup.bash

- This will call setup.sh and enables referring existing packages for ROS commands such as roscd. 

Create ROS package

catkin_create_pkg beginner_tutorials std_msgs rospy roscpp

catkin_create_pkg beginner_tutorials std_msgs rospy roscpp

- beginner_tutorials: package name / std_msgs, rospy,roscpp: package dependencies 

Move to ROS folder & check dependencies

roscd beginner_tutorials

rospack depends1 beginner_tutorials

Check ROS nodes

rosnode list

rosnode info /rosout

Run ROS package

rosrun turtlesim turtlesim_node

rosrun turtlesim turtlesim_node

- turtlesim: package name / turtlesim_node: node name

rosrun rqt_graph rqt_graph

Check ROS topics

rostopic list -v

Published topics:

 * /turtle1/color_sensor [turtlesim/Color] 1 publisher

 * /turtle1/cmd_vel [geometry_msgs/Twist] 1 publisher

 * /rosout [rosgraph_msgs/Log] 3 publishers

 * /rosout_agg [rosgraph_msgs/Log] 1 publisher

 * /turtle1/pose [turtlesim/Pose] 1 publisher

Subscribed topics:

 * /turtle1/cmd_vel [geometry_msgs/Twist] 1 subscriber

 * /rosout [rosgraph_msgs/Log] 1 subscriber

 * /statistics [rosgraph_msgs/TopicStatistics] 1 subscriber

rostopic echo /turtle1/cmd_vel

rostopic echo /turtle1/cmd_vel

linear: 

  x: 2.0

  y: 0.0

  z: 0.0

angular: 

  x: 0.0

  y: 0.0

  z: 0.0

 

rostopic type /turtle1/cmd_vel | rosmsg show

rostopic type /turtle1/cmd_vel | rosmsg show

geometry_msgs/Vector3 linear

  float64 x

  float64 y

  float64 z

geometry_msgs/Vector3 angular

  float64 x

  float64 y

  float64 z

rostopic pub /turtle1/cmd_vel geometry_msgs/Twist -r 1 -- '[2.0, 0.0, 0.0]' '[0.0, 0.0, -1.8]'

rostopic pub /turtle1/cmd_vel geometry_msgs/Twist -r 1 -- '[2.0, 0.0, 0.0]' '[0.0, 0.0, -1.8]'

RQT Topic Monitor

rosrun rqt_gui rqt_gui

: Run blank rqt qui

plugin->Topics->Topic Monitor

plugin->Topics->Message Publisher

This enables a nice interface for identifying existing ROS topics and publishing messages to subscribers. 

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