Example 10: Industrial robot with GPIO interfaces

This demo shows how to interact with GPIO interfaces.

The RRBot URDF files can be found in the description/urdf folder.

  1. To check that RRBot descriptions are working properly use following launch commands

    ros2 launch ros2_control_demo_example_10 view_robot.launch.py

  2. To start RRBot example open a terminal, source your ROS2-workspace and execute its launch file with

    ros2 launch ros2_control_demo_example_10 rrbot.launch.py

    The launch file loads and starts the robot hardware and controllers.

  3. Check if the hardware interface loaded properly, by opening another terminal and executing

    ros2 control list_hardware_interfaces

    command interfaces
    flange_analog_IOs/analog_output1 [available] [claimed]
    flange_vacuum/vacuum [available] [claimed]
    joint1/position [available] [claimed]
    joint2/position [available] [claimed]
state interfaces
    flange_analog_IOs/analog_input1
    flange_analog_IOs/analog_input2
    flange_analog_IOs/analog_output1
    flange_vacuum/vacuum
    joint1/position
    joint2/position

    In contrast to the RRBot of example_1, you see in addition to the joints now also GPIO interfaces.

  4. Check if controllers are running by

    ros2 control list_controllers

    joint_state_broadcaster[joint_state_broadcaster/JointStateBroadcaster] active
gpio_controller     [ros2_control_demo_example_10/GPIOController] active
forward_position_controller[forward_command_controller/ForwardCommandController] active

  5. If you get output from above you can subscribe to the /gpio_controller/inputs topic published by the GPIO Controller using ROS 2 CLI interface:

    ros2 topic echo /gpio_controller/inputs

    interface_names:
- flange_analog_IOs/analog_output1
- flange_analog_IOs/analog_input1
- flange_analog_IOs/analog_input2
- flange_vacuum/vacuum
values:
- 0.0
- 1199574016.0
- 1676318848.0
- 0.0

  6. Now you can send commands to the GPIO Controller using ROS 2 CLI interface:

    ros2 topic pub /gpio_controller/commands std_msgs/msg/Float64MultiArray "{data: [0.5,0.7]}"

    You should see a change in the /gpio_controller/inputs topic and a different output in the terminal where launch file is started, e.g.

    [RRBotSystemWithGPIOHardware]: Got command 0.5 for GP output 0!
[RRBotSystemWithGPIOHardware]: Got command 0.7 for GP output 1!

Files used for this demos

Controllers from this demo