How to build and run create3_examples

[tgkell]

I'm trying to run the create3_examples python dance example on an Ubuntu 20.04 machine. I have Ros2 installed and I can see the 25 or so create3 topics with "ros2 topic list". I can successfully run the "dock" and "undock" CLI examples given on the Create3 docs API page, but I'm trying to get the python example to run now.

Here are the issues I'm having:

1. The README.md says: First, source your ROS 2 workspaces with all the required dependencies. I think I need help with this. I have my .bashrc set up according to the Create 3 ROS2 installation instructions, which does (among other things) "source /opt/ros/galactic/setup.bash". The other dependency listed is irobot_create_msgs, which I didn't know how to address, and that might be my problem.
2. Following the create3_examples README, I did the "rosdep install --from-path src --ignore-src -yi" and that did about 2000 lines of work. I noticed in the output there lines saying Add distro "foxy" Add distro "galactic" Add distro "humble" Add distro "melodic" Add distro "noetic" Add distro "rolling" At any rate, it finished without apparent errors and a last line that says "#All required rosdeps installed successfully". But there is no install directory anywhere for the command "source ~/create3_examples_ws/install/local_setup.sh", so I wasn't able to do that part.
3. I changed dirs to create3_examples_py, where the README.md and another create3_examples_py dir can be seen, and did "ros2 run create3_examples_py create3_dance" but the output is
   Package 'create3_examples_py' not found

So, it seems I need to start over and get the irobot_create_msgs dependency satisfied, and figure out why building the examples does not give me an install directory. For irobot_create_msgs, I cloned the repository and did a
"colcon build --packages-up-to irobot_create_msgs". I came up with that command by trying to adapt an example from the ROS2 docs. It seemed to finish without errors, and I got an "install" directory, and I was able to "source install/local_setup.bash". But that didn't seem to affect anything. Do I need to explicitly set up all the irobot messages in the package one by one?

I'd appreciate any help anyone can offer. I'm interested in getting the python dance example to work.

[shamlian]

The Create 3 examples in subfolders all first require the steps in the README in the root folder. The build instructions are run once from your home directory per install, and the initialization instructions are run once per new terminal session.

For your first question, the "source your ROS 2 workspaces with all the required dependencies" is referring to the instruction given as the intialization step: source ~/create3_examples_ws/install/local_setup.sh .

For your second question, ~/create3_examples_ws/install/local_setup.sh should have been created when you ran the build instructions in the root folder README from your home directory. If you did not run them at all, or did not run them from your home directory, you will need to do that.

For your third question, that won't work until you've sourced your local setup, which is what you weren't able to do from your first question. Where exactly are you running these examples from? (What's the path? Type pwd .)

The rosdep step should pull the package dependencies. You should not have to explicitly install them.

[tgkell]

Thank you for the quick response.

I tried replying once before, but that reply didn't seem to appear here. Perhaps the file I attached to that reply is too big, and the reply got filtered out.

I'll try again more briefly:

I'm following the instructions in the create3_examples/README.md file to try to install/run the create3_examples. I can successfully complete the "build instructions" section, but the "initialization instructions" section doesn't work because after completing the "build instructions", in my case, there is no ~/create3_examples_ws/install/local_setup.sh. I begin the "build instructions" in my home directory, and here are the build_instructions I am following:

mkdir -p create3_examples_ws/src
cd create3_examples_ws/src
git clone https://github.com/iRobotEducation/create3_examples.git
cd ..
rosdep install --from-path src --ignore-src -yi
colcon build

I'm careful to follow these instructions exactly, starting in my home directory. These instructions complete without errors (and over 2000 lines of output!), when initiated from my home directory, but I cannot proceed to the "Initialization instructions" step which is source ~/create3_examples_ws/install/local_setup.sh. There is no "install" directory at that location, or anywhere.

I am grateful for any hints as to what I am doing wrong.

[tgkell]

whoops, I see my problem. My bad, I still needed to run the "colcon build" command, and the install directory does exist after that. Right now I am seeing:
ros2 run create3_examples_py create3_dance
[INFO] [1658032651.563541078] [dance_command_publisher]: service not available, waiting again...
[INFO] [1658032652.569715657] [dance_command_publisher]: service not available, waiting again...

Which is an improvement, it seems to be trying. However, the create3 (undocked) is not responding.. But still, progress!

[Rebecca-iRobot]

Hi there! I have an instructional video that should be helpful to you when building the Create 3 examples repository :) While the instructions specifically walk through building the repository/dependencies, it should get you 95% there! I'll send it along in a couple of hours.