ros2-keyboard

This node uses the SDL library to grab keypresses. To do so, it opens a window where input is received. This window needs to becurrently focused, otherwise this node will not receive any key presses.

Install

1. Create a new workspace.
2. $ cd /path/to/your_ws/src
3. Clone this repository

• (ssh) $ git clone git@github.com:cmower/ros2-keyboard.git
• (https) $ git clone https://github.com/cmower/ros2-keyboard.git

4. Install SDL 1.2 with the command sudo apt install libsdl1.2-dev.
5. $ cd /path/to/your_ws
6. $ colcon build

Nodes

keyboard

Publishes keyboard events when the window is focused.

• Published topics: keydown and keyup (keyboard_msgs/Key)
• Parameters
  • allow_repeat (bool): Enables or disables the keyboard repeat rate. Default is false.
  • repeat_delay (int): How long the key must be pressed before it begins repeating. Default is SDL_DEFAULT_REPEAT_DELAY.
  • repeat_interval (int): Key replay speed. Default is SDL_DEFAULT_REPEAT_INTERVAL.

keyboard_to_joy.py

Converts keyboard events to a joy message.

• Published topic: joy (sensor_msgs/Joy)
• Subscribed topics: keydown and keyup (keyboard_msgs/Key)
• Parameters
  • config_file_name (str): File name for the configuration file. See here for an example.
  • sampling_frequency (int): Rate (Hz) at which joy messages are published. Default is 50.

Example:

In one terminal, start the keyboard node.

ros2 run keyboard keyboard

In a second terminal, start the keyboard_to_joy.py node.

ros2 run keyboard keyboard_to_joy.py --ros-args \
  -p config_file_name:=`ros2 pkg prefix keyboard`/share/keyboard/config/example_config.yaml