What Is This?

This demo creates and runs two ROS 2 nodes individually, namely dummy_laser and dummy_joint_states.

dummy_laser publishes sensor_msgs/msg/LaserScan on a ROS 2 publisher topic, /scan.

dummy_joint_states publishes sensor_msgs/msg/JointState on a ROS 2 publisher topic, /joint_states.

Both dummy_laser and dummy_joint_states are dependencies of dummy_robot_bringup, and are usually expected to be run from the launch file there. Please refer to dummy_robot_bringup.

Build

colcon build --packages-select dummy_sensors

Run

1 - dummy_laser

ros2 run dummy_sensors dummy_laser

# Terminal Output
[INFO] [1658564972.776089023] [dummy_laser]: angle inc:	0.004363
[INFO] [1658564972.776138078] [dummy_laser]: scan size:	1081
[INFO] [1658564972.776148752] [dummy_laser]: scan time increment: 	0.000000

2 - dummy_joint_states

ros2 run dummy_sensors dummy_joint_states

Verify

A similar terminal output should be seen after running commands described in the Run section above:

1 - dummy_laser

# Open new terminal.
ros2 topic echo /scan

# Terminal Output
---
header:
  stamp:
    sec: 1658569107
    nanosec: 51491730
  frame_id: single_rrbot_hokuyo_link
angle_min: -2.356194496154785
angle_max: 2.356194496154785
angle_increment: 0.004363323096185923
time_increment: 2.7777778086601757e-05
scan_time: 0.03999999910593033
range_min: 0.0
range_max: 10.0
ranges:
- 0.39602306485176086
- 0.39602306485176086
- 0.39602306485176086
- 0.39602306485176086
- 0.39602306485176086
- 0.39602306485176086
- 0.39602306485176086
- '...'
intensities: []
---

2 - dummy_joint_states

# Open new terminal.
ros2 topic echo /joint_states

# Terminal Output
---
header:
  stamp:
    sec: 1658569569
    nanosec: 414505214
  frame_id: ''
name:
- single_rrbot_joint1
- single_rrbot_joint2
position:
- -0.033653174530243454
- -0.033653174530243454
velocity: []
effort: []
---
header:
  stamp:
    sec: 1658569569
    nanosec: 434418040
  frame_id: ''
name:
- single_rrbot_joint1
- single_rrbot_joint2
position:
- -0.13326191698696957
- -0.13326191698696957
velocity: []
effort: []
---
header:
  stamp:
    sec: 1658569569
    nanosec: 454443902
  frame_id: ''
name:
- single_rrbot_joint1
- single_rrbot_joint2
position:
- -0.2315391504196944
- -0.2315391504196944
velocity: []
effort: []
---
header:
  stamp:
    sec: 1658569569
    nanosec: 474417706
  frame_id: ''
name:
- single_rrbot_joint1
- single_rrbot_joint2
position:
- -0.3275029211980919
- -0.3275029211980919
velocity: []
effort: []
---
header:
  stamp:
    sec: 1658569569
    nanosec: 494442418
  frame_id: ''
name:
- single_rrbot_joint1
- single_rrbot_joint2
position:
- -0.4201943910459491
- -0.4201943910459491
velocity: []
effort: []
---

References

• sensor_msgs/msg/LaserScan Message Format: https://github.com/ros2/common_interfaces/blob/rolling/sensor_msgs/msg/LaserScan.msg
• sensor_msgs/msg/JointState Message Format: https://github.com/ros2/common_interfaces/blob/rolling/sensor_msgs/msg/JointState.msg

Changelog for package dummy_sensors

0.37.0 (2025-04-25)

0.36.0 (2025-04-25)

• Uniform CMAKE min VERSION (#714) demo_nodes_cpp/CMakeLists.txt require cmake min version 3.12 other modules cmake 3.5. It is proposed to standardize with version 3.12. This also fixes cmake <3.10 deprecation warnings
• Use target_link_libraries instead of ament_target_dependencies (#707)
• Contributors: Shane Loretz, mosfet80

0.35.1 (2024-11-20)

0.35.0 (2024-10-03)

0.34.2 (2024-07-29)

0.34.1 (2024-06-17)

• Update dummy_sensors readme to echo the correct topic (#675)
• Contributors: jmackay2

0.34.0 (2024-04-26)

0.33.2 (2024-03-28)

• Update maintainer list in package.xml files (#665)
• Contributors: Michael Jeronimo

0.33.1 (2024-02-07)

0.33.0 (2024-01-24)

0.32.1 (2023-12-26)

0.32.0 (2023-11-06)

0.31.1 (2023-09-07)

0.31.0 (2023-08-21)

0.30.1 (2023-07-11)

0.30.0 (2023-06-12)

0.29.0 (2023-06-07)

0.28.1 (2023-05-11)

• Fix unstable LaserScan status for rviz2 (#614)
• Contributors: Chen Lihui

0.28.0 (2023-04-27)

0.27.0 (2023-04-13)

0.26.0 (2023-04-11)

0.25.0 (2023-03-01)

0.24.1 (2023-02-24)

0.24.0 (2023-02-14)

• Added README.md for dummy_sensors (#573)
• Update the demos to C++17. (#594)
• [rolling] Update maintainers - 2022-11-07 (#589)
• Contributors: Audrow Nash, Chris Lalancette, Gary Bey

0.23.0 (2022-11-02)

0.22.0 (2022-09-13)

0.21.0 (2022-04-29)

0.20.1 (2022-04-08)

0.20.0 (2022-03-01)

0.19.0 (2022-01-14)

0.18.0 (2021-12-17)

• Update maintainers to Audrow Nash and Michael Jeronimo (#543)
• Contributors: Audrow Nash

0.17.0 (2021-10-18)

0.16.0 (2021-08-11)

0.15.0 (2021-05-14)

0.14.2 (2021-04-26)

0.14.1 (2021-04-19)

0.14.0 (2021-04-06)

0.13.0 (2021-03-25)

0.12.1 (2021-03-18)

0.12.0 (2021-01-25)

0.11.0 (2020-12-10)

• Update the package.xml files with the latest Open Robotics maintainers (#466)
• Contributors: Michael Jeronimo

0.10.1 (2020-09-21)

0.10.0 (2020-06-17)

0.9.3 (2020-06-01)

0.9.2 (2020-05-26)

0.9.1 (2020-05-12)

0.9.0 (2020-04-30)

0.8.4 (2019-11-19)

0.8.3 (2019-11-11)

0.8.2 (2019-11-08)

0.8.1 (2019-10-23)

0.8.0 (2019-09-26)

0.7.6 (2019-05-30)

• Fix memory leak in the dummy robot examples. (#361)
• Contributors: Chris Lalancette

0.7.5 (2019-05-29)

0.7.4 (2019-05-20)

0.7.3 (2019-05-10)

0.7.2 (2019-05-08)

• changes to avoid deprecated API's (#332)
• Corrected publish calls with shared_ptr signature (#327)
• Contributors: William Woodall, ivanpauno

0.7.1 (2019-04-26)

0.7.0 (2019-04-14)

0.6.2 (2019-01-15)

0.6.1 (2018-12-13)

0.6.0 (2018-12-07)

• Added semicolons to all RCLCPP and RCUTILS macros. (#278)
• Contributors: Chris Lalancette

0.5.1 (2018-06-28)

0.5.0 (2018-06-27)