ROS2 Debugging Best Practices

Checking TF Transforms

CRITICAL: Always use long timeouts (10-15 seconds minimum).

Tools like tf2_echo need 1-2 seconds to initialize their TF buffer before they can query transforms.

# CORRECT: Long timeout allows TF buffer to initialize
timeout 15 bash -c 'ros2 run tf2_ros tf2_echo map BASE 2>&1' | head -20

# WRONG: Short timeout often fails before transform data appears
timeout 3 ros2 run tf2_ros tf2_echo map BASE  # Will likely fail

Why This Matters

• tf2_echo needs 1-2 seconds to initialize its TF buffer
• During initialization, it prints "frame does not exist" errors (this is normal)
• Short timeouts (3-5s) often trigger before real transform data appears
• Piping to head can cause premature termination without proper delays

Checking ROS Topics

# List all topics
ros2 topic list

# Check topic frequency (let it run for a few seconds)
timeout 10 ros2 topic hz /your_topic

# Echo topic data with timeout
timeout 10 ros2 topic echo /your_topic --once

# Check topic info
ros2 topic info /your_topic --verbose

Common ROS2 Debugging Commands

# Check node status
ros2 node list
ros2 node info /your_node

# Service debugging
ros2 service list
ros2 service call /service_name std_srvs/srv/Empty "{}"

# Parameter inspection
ros2 param list /your_node
ros2 param get /your_node parameter_name

# View TF tree
ros2 run tf2_tools view_frames

tmux Integration

When running ROS scripts, open a new permanent tmux window:

# If in tmux session, create new window (counting starts from 1)
tmux new-window -n ros2

# Run your ROS command (keep the pane alive on failure so output is inspectable)
tmux send-keys -t ros2 "bash -lc 'ros2 launch your_package your_launch.py; exec bash -i'" C-m

# Always capture pane output to verify
sleep 0.5
tmux capture-pane -p -S -200