This ROS 2 package overrides the geometry_msgs/Twist topic in response to an emergency stop (E-STOP) signal received via serial connection.
$ cd ~/<path_to_your_workspace>/src
$ git clone https://github.com/KBKN-Autonomous-Robotics-Lab/estop_ros.git
$ wstool merge estop_ros/estop_ros.rosinstall
$ wstool update
$ rosdep install -r -y -i --from-paths .
$ cd ~/<path_to_your_workspace> && colcon build
$ ros2 launch estop_ros estop_control.launch.xml