Athena Code

This repository contains all the code for UMDLoop's 2025-26 rover, Athena.

When cloning, be sure to use git clone --recursive [URL to Git repository] to pull in the submodules found in src/third-party. Alternatively, run git submodule update --init --recursive if you have already cloned.

How To Use

Hardware Setup

• Ensure CAN Bus is connected and hardware is configured to the correct IDs
• Verify that each of the ros2_control xacro files (in src/description/ros2_control/) have the correct IDs inside of the node_id parameter for each joint

CAN Setup

Hardware:

./src/athena-code/src/tools/scripts/can_setup.sh

Virtual:

./src/athena-code/src/tools/scripts/virtual_can_setup.sh

Use ip link to verify that can0 or vcan0 is up.

Building

1. Install required dependencies:

rosdep install --from-paths src -y --ignore-src

2. Build the workspace:

colcon build --symlink-install

3. Source the workspace:

source install/setup.bash

---

Controller Switching

All subsystems use a controller switching service. Open a new terminal, source the workspace, and call:

source install/setup.bash
ros2 service call /set_controller msgs/srv/SetController "{controller_names: [CONTROLLER_NAME]}"

Only one motion controller should be active at a time (alongside the joint_state_broadcaster).

---

Testing

Arm

Launch

Hardware:

ros2 launch arm_bringup athena_arm.launch.py use_mock_hardware:=false

Mock (no hardware):

ros2 launch arm_bringup athena_arm.launch.py use_mock_hardware:=true

PS4 Controller

• Base Yaw: Left/Right on Left Joystick (Axes 0)
• Shoulder Pitch: Up/Down on Left Joystick (Axes 1)
• Elbow Pitch: Up/Down on Right Joystick (Axes 3)
• Wrist Pitch: Up/Down on Left Joystick AND O button (Axes 1)
• Wrist Roll: Left/Right on Left Joystick AND O button (Axes 0)
• Open Claw (max speed): Left Bumper (Button 5)
• Close Claw (max speed): Right Bumper (Button 4)
• Open Claw (speed control): Left Trigger (Axes 5)
• Close Claw (speed control): Right Trigger (Axes 4)

Velocity Testing

1. Switch to velocity controller using the controller switching service
2. In a new terminal:

ros2 topic pub /velocity_controller/commands std_msgs/msg/Float64MultiArray "{data: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]}"

Joint Trajectory Testing

1. Switch to joint trajectory controller using the controller switching service
2. In a new terminal:

ros2 action send_goal /joint_trajectory_controller/follow_joint_trajectory control_msgs/action/FollowJointTrajectory "{ \
  trajectory:{ \
    joint_names: ['base_yaw', 'shoulder_pitch', 'elbow_pitch', 'wrist_pitch', 'wrist_roll', 'gripper_claw', 'actuator'], \
    points: [ \
      {positions: [0.0, -1.0, -2.0, -1.0, -0.16, 0.0, 0.0], time_from_start: {sec: 3, nanosec: 0}}, \
    ] \
  } \
}"

---

Drive

Launch

Hardware:

ros2 launch drive_bringup athena_drive.launch.py use_mock_hardware:=false

Mock (no hardware):

ros2 launch drive_bringup athena_drive.launch.py use_mock_hardware:=true

The default controller is single_ackermann_controller. To use the built-in ackermann steering controller instead:

ros2 launch drive_bringup athena_drive.launch.py robot_controller:=ackermann_steering_controller

---

Science

Launch

Hardware:

ros2 launch science_bringup athena_science.launch.py use_mock_hardware:=false

Mock (no hardware):

ros2 launch science_bringup athena_science.launch.py use_mock_hardware:=true

---

How To Contribute

Learning Git

If you're new to Git and GitHub, start with this beginner-friendly tutorial: GitHub's Hello World Guide

For a more comprehensive introduction, check out: Git and GitHub Tutorial for Beginners

Setting up Git

Before you can contribute, you'll need to have Git installed and configured on your machine:

1. Install Git - Follow GitHub's guide to set up Git on your system
2. Configure Git - Set your username and email that will be associated with your commits

SSH Keys

To securely authenticate with GitHub without entering your password each time, set up SSH keys:

1. Check for existing SSH keys - See if you already have SSH keys: Checking for existing SSH keys
2. Generate a new SSH key - If needed, create a new SSH key pair: Generating a new SSH key
3. Add SSH key to GitHub - Upload your public key to your GitHub account: Adding a new SSH key to your GitHub account

Making a Pull Request (PR)

Once you're set up, here's how to contribute your changes:

1. Fork the repository - Create your own copy of the repository: Fork a repo

2. Clone your fork - Download your forked repository to your local machine using git clone.

3. Create a feature branch - Make a new branch for your specific feature or fix:

git checkout -b feature/your-feature-name

4. Make your changes - Write your code, test it thoroughly, and commit your changes

5. Push to your fork - Upload your feature branch to your GitHub fork

git push origin feature/your-feature-name

6. Open a Pull Request - Submit your changes for review: Creating a pull request from a fork

Your PR will be reviewed by your lead, and once approved, it will be merged into the main codebase!