Livox ROS Driver - Message Alias Package

A ROS 2 package providing message definitions for legacy Livox ROS bag playback, solving compatibility issues when converting ROS 1 bags to ROS 2.

Problem Background

When converting ROS 1 bag files containing Livox messages to ROS 2 format using rosbags, the converted bags reference message types that don't exist in ROS 2:

• livox_ros_driver/msg/CustomMsg
• livox_ros_driver/msg/CustomPoint

This package provides these message definitions as aliases, enabling playback of converted Livox bags in ROS 2 environments.

Features

• CustomMsg: Complete Livox pointcloud message format with header, timing, and point data
• CustomPoint: Individual point format with position, reflectivity, and Livox-specific metadata
• ROS 2 Compatible: Built for ROS 2 using ament_cmake and rosidl

Message Definitions

CustomMsg

std_msgs/Header header    # ROS standard message header
uint64 timebase           # The time of first point
uint32 point_num          # Total number of pointclouds
uint8  lidar_id           # Lidar device id number
uint8[3]  rsvd            # Reserved use
CustomPoint[] points      # Pointcloud data

CustomPoint

uint32 offset_time      # offset time relative to the base time
float32 x               # X axis, unit:m
float32 y               # Y axis, unit:m
float32 z               # Z axis, unit:m
uint8 reflectivity      # reflectivity, 0~255
uint8 tag               # livox tag
uint8 line              # laser number in lidar

Installation

Prerequisites

• ROS 2 (Jazzy/Humble/Rolling)
• colcon build tools

Build from Source

1. Create/Navigate to your workspace:

   mkdir -p ~/ros2_ws/src
   cd ~/ros2_ws/src

2. Clone this repository:

   git clone https://github.com/your-username/livox_ros_driver.git

3. Build the package:

   cd ~/ros2_ws
   colcon build --packages-select livox_ros_driver

4. Source the workspace:

   source install/setup.bash

Usage

Verify Installation

Check if the messages are available:

# List available interfaces
ros2 interface list | grep livox

# Show message definitions
ros2 interface show livox_ros_driver/msg/CustomMsg
ros2 interface show livox_ros_driver/msg/CustomPoint

Python Usage

from livox_ros_driver.msg import CustomMsg, CustomPoint

# Create message instances
custom_msg = CustomMsg()
custom_point = CustomPoint()

C++ Usage

#include "livox_ros_driver/msg/custom_msg.hpp"
#include "livox_ros_driver/msg/custom_point.hpp"

// Use in your code
livox_ros_driver::msg::CustomMsg msg;
livox_ros_driver::msg::CustomPoint point;

Converting ROS 1 Bags

1. Convert your ROS 1 bag to ROS 2:

   # Install rosbags converter
   pip install rosbags
   
   # Convert bag file
   rosbags-convert your_livox_bag.bag --dst your_livox_bag_ros2/

2. Ensure this package is built and sourced in your workspace

3. Play the converted bag:

   ros2 bag play your_livox_bag_ros2/

Package Structure

livox_ros_driver/
├── CMakeLists.txt
├── package.xml
├── msg/
│   ├── CustomMsg.msg
│   └── CustomPoint.msg
└── README.md

Dependencies

• std_msgs
• builtin_interfaces
• rosidl_default_generators (build)
• rosidl_default_runtime (exec)

License

Apache License 2.0

Contributing

Issues and pull requests are welcome! Please ensure any contributions maintain compatibility with the original Livox message formats.

Related Links

• rosbags - ROS bag conversion tool
• Livox SDK
• ROS 2 Message and Service Development