RoverFlake - ROS 1 (Noetic) / Ubuntu 20.04

Our new, ROS 1 Noetic repository.
Our ROS2 Humble/Foxy repository is RoverFlake2 Our Firmware repository is FirmFlake Make sure to clone reccursively git clone https://github.com/UBC-Snowbots/RoverFlake.git --recursive We are using branches only, you are free to make a fork if you are experienced with git, but using git with 1 remote is going to be easier. We reccommend using gitt CLI if you have experience with it. We reccomend the git GUI from VS code if you havent used git before to pull/push code and manage commits (easiest to use git CLI to set up repo)

git remote -v should return:

origin https://github.com/UBC-Snowbots/RoverFlake.git (fetch)

origin https://github.com/UBC-Snowbots/RoverFlake.git (push)

To run or build any of the ROS code, you will need to set up an ubuntu enviroment. To see how, read the "setup_ubuntu.md" in "resources" (https://github.com/UBC-Snowbots/RoverFlake/blob/fce38688cf4b68fb9d10681cf8c75e355d8a5337/resources/setup_ubuntu.md)

CIRC Competition Rules: https://circ.cstag.ca/2023/tasks/

Tips for New Members

Tutorials and advice for new members.

Terminal

First of all, if you're new to the Ubuntu command line: it is primarily used over the graphical user interface as it allows you to do more.

Github

In case you're new to GitHub, get started with this tutorial

Pretty cool right? Now you're wondering how you can use GitHub from the terminal/command line, it's called Git

Workflow

Now you're wondering how we develop our software, the first place to start is understanding how our workflow works. We use the Forking Workflow, which you can learn more about under Github Conventions in README.md (located in the same directory you opened this readme from) and other important information you should know. If you have questions, you may find your answers over there.

C++

This is the language we use to develop most of our software, so if you are new with C++, understand the fundamentals from this tutorial, but there are much more resources online as well.

ROS

By now you understand the basics of ROS, but to learn more about it, you can complete the intermediate tutorials or brush up on the basics if you need to here

General Advice

Rarely will your Github issues contain all the information that you need to resolve them. Using google to search for that missing piece you need is sometimes useful (think like an optimist when you're understanding/interpreting your project/issue: "If only I knew how to do...", then search "how to do..."), or of course don't hesitate to ask for help, clarification, or just more information from any of the software leads.

Remember it is much better to get help when you're stuck than to waste time trying to figure out what's wrong. This way, you're more or less continuously progressing, and as a whole, we develop efficiently and our software stack progresses.

Conventions

Github Conventions

• We follow the Centrilized Workflow:
  • what it is
  • how to use it
• Only commit files that are essential for the system to run; do not put any photos or videos in here
• All files should be formatted properly. Formatting will... not be enforced with the clang-format tool.
  • To check and fix formatting, from the Snowflake repo run ./clang_format/fix_formatting.sh BRANCH_NAME, where BRANCH_NAME is the name of the branch you intend to merge your code into (ex. iarrc or core). This script will fix any improperly formatted code, but will refuse to change any files with uncommited changes (to prevent you losing work)
• Once your pull request has been reviewed and revised until it looks good from both your and the reviewers' sides, go ahead and Squash and Merge it, which will squash all the commits on your pull request into one and merge it to the target branch.
• Once you know you don't need your branch anymore, and all code is merged to another branch, then make sure to delete it.

Pull Requests

Below are some notes we would like to highlight about pull requests:

• before opening a pull request, quickly run through the pull request checklist and make sure you've satisfied everything
• Once your pull request has been approved, please proceed to merge and close the pull request yourself
• When your pull requests receive comments, please reply to each comment individually.
• If there were any fixes that were specific to resources you found (eg. stackoverflow thread), please comment them into the PR for future reference.
• On a similar note, if you made design decisions, please document them in the comments of the PR. We often go back to close PRs to look at why things were done a certain way. It is very helpful for us to know how you came up with your brilliant solution.

Coding Conventions

• Every .cpp and .h file should start with

/*
 * Created By: Someone
 * Created On: December 1st, 2000
 * Description: A quick description of what this file does/is for
 */

• Functions should be commented a la JavaDoc
• The Javadoc comment (below) should be directly above every function in the header file

/**
 * One line description of the function
 *
 * A longer and more in depth description of the function
 * if it is needed.
 * 
 * @param param_one the first parameter of the function
 * @param param_two the second parameter of the function whose
 *                  description goes longer than one line
 * @return what the function returns if it returns anything
 * 
 */

• Classes are CamelCase

• Variables are non_camel_case

• Constants are ALL_CAPS_WITH_UNDERSCORES

• Functions are camelCase

• Indentations are 4 spaces

• CMakeLists.txt files should be reduced to only contain the minimum amount of comments. The version in sample_package has all the comments left in (for the sake of verbosity), so for a more representative example of what yours should look like, see sb_vision/CMakeLists.txt (or really any package aside from sample_package)

Coordinate Systems

• We try to follow ROS standards, which can be found here
• x : forward
• y : left
• z : up

              +X
              ^
              |
      +θ  +<----->+ -θ
          |   |   |
          V   |   V
+Y <---------------------> -Y
              |
              |
              |
              V
              -X

Creating a new node

• If your node is at all complicated, then this format should be followed. For simple nodes, please see below
• Each node should be class based
• MyNode.h should contain your class declaration
• MyNode.cpp should contain your class definition
• my_node.cpp should be relatively small, and should just contain a main function to run your node
• my-node-test.cpp should contain all your gtest (unit test)
• my_node_rostest.cpp should contain your rostest (integrated test)
• For an example of this, please see src/sample_package

some_ros_package
|  CMakeLists.txt
|  package.xml
└───src
|   | MyNode.cpp 
|   | my_node.cpp
|
└───launch
|   | my_node.launch
|
└───include
|   | MyNode.h
| 
└───test
|   | my-node-test.cpp
|   | my_node_rostest.cpp
|   | sample_package_test.test

Creating a new simple node

• You will not be able to write unit tests for this type of node, so it must be extremely simple
• my_node.cpp will contain the entire node, and will probably contain a while(ros::ok()){} loop

some_ros_package
|  CMakeLists.txt
|  package.xml
└───src
|   | my_node.cpp

Launch files

• A launch file (ends in .launch) is an easy way to run multiple nodes with specified parameters with one single command. This is useful if a package has multiple nodes that needs to be run. A launch file can also launch other smaller launch files so it can be used to start every node needed for the robot to run properly. Reference here.
• To use the launch file, the command is: roslaunch package_name package_launch_file.launch

Testing

GTest

• GTest is our primary testing tool at the moment. The ROS wiki has a quick intro to it here, and we also strongly recommend you read Google's introduction to it [here] (https://github.com/google/googletest/blob/master/googletest/docs/Primer.md), then setup and write a few example tests before you start using it with ROS.
• Once you've setup your tests in ROS, run catkin_make run_tests to run them
• To test a specific package, run catkin_make run_tests_MY_PACKAGE_NAME

Rostest

• For tests which require more than one active node, i.e. integrated testing, the rostest framework provides a way to launch your test alongside all the nodes it requires. This is an extension on roslaunch enabling it to run test nodes. Special test nodes are nested within a <test></test> tag. This also needs a special entry under CMakelists as shown in the sample package. See more details here
• Similar to launch files, the command is: rostest package_name package_test_file.test.

Simulating with Gazebo

• You will always need to source the project before running gazebo, by moving to the project directory with cd ~/Snowflake and then source devel/setup.sh
• You will probably need a computer with an dedicated gpu, as gazebo sometimes works with intel integrated graphics, but generally not. If you do end up using a computer without a dedicated gpu, make sure to go in to sb_gazebo/urdf/**ROBOT_NAME**.gazebo and switch around the lidar settings (see comments in said file)
• All worlds should go in the sb_gazebo/worlds folder
• To launch a world, simply run the appropriate launch file in sb_gazebo/launch
• Once the world has launched, it is common for the robot to be initially unable to move. Just lift it up a bit in gazebo and drop it for this to be fixed
• You can manually control the robot with your keyboard, logitech, ps3, or xbox controller. To do so, simply cd ~/Snowflake and then source devel/setup.sh, then run the appriate launchfile from src/sb_gazebo/launch by running roslaunch LAUNCH_FILE.launch (from within the launch folder). Note: At least with PS3 controllers, you have to hold down L1 while using the joystick for the controller to work

Arduino Development

• When developing the firmware/Arduino parts of the software, we've made a complete arduino workspace in src/firmware. This way you don't need to worry about downloading the libraries yourself!
• In order to use this, go to your Arduino IDE's Preferences dialog box and use /your/path/to/Snowflake/src/firmware as your sketchbook directory. Open arduino sketches in the workspace and they will work!

Intel Realsense

Intel Realsense is a sensor that captures a 3D depth map of the environment in front of the sensor. This 3D depth map is called a point cloud, which is essentially just a list (vector in c++) that contains a bunch of points, where each point contains the x, y, and z coordinates, as well as a color value associated to it.

• Visualizing the input from the realsense: Run roslaunch realsense2_camera rs_rgbd.launch to launch realsense. You should be able to see the point cloud at the topic named /camera/depth_registered/points in rviz.
• Recording a rosbag from the Realsense: Recording a rosbag from the Realsense is useful, because you can record the input from the sensor and play it as many time as you want after recording it. That way, you don't need the physical sensor and you don't to "capture" the same thing every time you run it.
  1. Launch realsense using roslaunch realsense2_camera rs_rgbd.launch.
  2. Record a rosbag by running rosbag record /camera/depth_registered/points <options>. See rosbag record -h for the list of options. To stop the recording, just press ctrl+c. E.g. rosbag record /camera/depth_registered/points --split --duration 1m --max-splits 3 -o ../rosbags/tennis_ball/ - split files every 1 minute, split for maximum of 3 times, and store the rosbag in ../rosbags/tennis_ball/ folder.
  3. Stop the realsense node (ctrl+c the process launched in step 1)
  4. Run rosbag play path/to/rosbag/file -l. path/to/rosbag/file is the path to the rosbag generated in step 2. Note that the -l flag loops the recording so it will play forever until you terminate it manually (using ctrl+c).
  5. Open rviz. You should be able to see the recording of the point cloud at /camera/depth_registered/points.

Debugging Tips

• If something is happening that does not seem to correspond to your code, (ex. if your node is subscribing to the totally wrong topic) try deleting the build and devel folders (if present) to remove any "cached" information