Event-Based Keyboard Teleop

Standard teleop_twist_keyboard is the required first teleop tool for this guide. Use this extra only if you want a small GUI window that publishes movement while a key is physically held and sends stop commands when it is released.

This is optional reused utility code. It is not your required autonomous routine, and it is not a reason to copy the whole OrphBot package into your submission.

The OrphBot package includes a Tk teleop node at:

orphbot/orphbot/keyboard_teleop.py

That file publishes geometry_msgs/msg/Twist on cmd_vel, uses W/S/A/D for movement, Space or X for stop, plus/minus for speed changes, and Q to quit. The repository is MIT licensed, so include the license notice or attribution required by that license if you reuse the file.

Run this on the computer that will drive the robot:

sudo apt update
sudo apt install -y python3-tk

On WSL, this also needs a working GUI display such as WSLg.

Use a separate example folder so your robot package stays yours.

WORKSPACE_NAME="cool_rover_ws"
PACKAGE_NAME="cool_rover"

cd ~
git clone https://github.com/SharKingStudios/orphbot-package.git orphbot-example
cp \
  ~/orphbot-example/orphbot/orphbot/keyboard_teleop.py \
  ~/"$WORKSPACE_NAME"/src/"$PACKAGE_NAME"/"$PACKAGE_NAME"/keyboard_teleop.py

Do not copy OrphBot’s motor node, IMU node, odometry node, launch files, or config as your submission. This extra is only about reusing one desktop teleop utility.

Open your copied keyboard_teleop.py and check:

• the node name is keyboard_teleop
• it creates a publisher for cmd_vel
• W, S, A, and D set linear.x and angular.z
• the stop function publishes zero motion
• the window title can be changed if you want it to show your robot name

Add a console_scripts entry in your setup.py.

entry_points={
    'console_scripts': [
        'event_teleop = cool_rover.keyboard_teleop:main',
    ],
},

Build and source the workspace:

WORKSPACE_NAME="cool_rover_ws"
PACKAGE_NAME="cool_rover"

cd ~/"$WORKSPACE_NAME"
source /opt/ros/jazzy/setup.bash
colcon build --symlink-install
source install/setup.bash
ros2 pkg executables "$PACKAGE_NAME"

Expected result: the executable list includes cool_rover event_teleop if you used the example names.

Use this after your robot-side motor node and watchdog are working.

PACKAGE_NAME="cool_rover"
ros2 run "$PACKAGE_NAME" event_teleop

Focus the small window. Hold W, S, A, or D to publish movement. Release keys to stop that direction. Press Space or X for an immediate stop burst. Press Q to quit.

Before driving on the floor, inspect the command stream:

ros2 topic info /cmd_vel --verbose
ros2 topic echo /cmd_vel

Only one command publisher should be active during normal driving unless you wrote a command arbiter or mux. Keep the robot-side watchdog enabled even when this teleop works perfectly.