ROS Workspace Setup

This document explains how to build the ROS Workspace, the use cases for different nodes are described here.

How to Clone

The workstation_ros directory contains a ROS 2 workspace that uses git submodules. To clone it properly:

git clone --recurse-submodules -b workstation_ros https://github.com/IMRCLab/pololu3pi2040-rs.git <target_directory>
cd <target_directory>

If you already cloned without --recurse-submodules, run:

git submodule update --init --recursive

How to Build

From the workspace root:

source /opt/ros/<ros_distro>/setup.bash
colcon build 

Source the environment before running any nodes:

source install/setup.bash

Troubleshooting

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Controller Interface and Robot Issues

Controller not detected:

# Check if controller is recognized
ls /dev/input/js*
# Should show /dev/input/js0 or similar

# Test controller input
ros2 run joy joy_node
ros2 topic echo /joy

No robot response:

1. Check robot radio URIs in controller_interface.yaml - Are the commands sent to the correct robot addresses?
2. Verify robots are flashed with correct firmware (to accept commands)
3. Could it be that the robot has no SD Card? Has the SD Card a trajectory (TRJ0001.JSN - use exactly THIS NAME)? Is the log full (capped at TR99)?
4. "Weird behavior" - Does the robot have proper mocap data? Does the robot have an SD Card with the right robot configuration on it (ROBOTCFG_3Pi.CFG or ROBOTCFG_ZUMO.CFG)?
5. Check ROS logs for connection errors:

   ros2 launch pololu controller_interface_launch.py --screen
   

Build errors:

# Clean build
rm -rf build/ install/ log/
colcon build --cmake-args -DCMAKE_EXPORT_COMPILE_COMMANDS=ON

Submodule issues:

# Reset all submodules and pull them again recursively
git submodule deinit --all
git submodule update --init --recursive

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Safety Features

• Emergency stop functionality (BACK button stops all robots) - helpful when running multi-robot experiments
• Individual robot control prevents accidental commands to wrong robots