17.3. Microros Subscriber Performance Test

17.3.1. Overview

The subscriber example demonstrates the message subscription function of microros nodes through XRCE-Client.

One ubuntu host with ROS2 foxy version installed.
Connect the host to the development board using a USB to serial port. The serial port number used by the development board can be found in board.h.

ros2 foxy install:

1.Installation steps on the official website [https://docs.ros.org/en/foxy/Installation/Alternatives/Ubuntu-Development-Setup.html].

2.Installing through APT(If necessary，change the source of ubuntu)

sudo apt update
sudo apt install ros-foxy-desktop

After installing ROS2 foxy, it is necessary to install the agent on the host side, which is installed through Docker

docker run -it --rm --net=host -v /dev/shm:/dev/shm -v /dev:/dev --privileged microros/micro-ros-agent:foxy serial --dev ${serial}

If you encounter a situation where the serial port cannot be opened, please change the permissions for the serial port

sudo chmod -R 777 ${serial}

After running the agent, reset the board.

Open a new terminal

source /opt/ros/foxy/setup.bash

type ros2 node list You can see the ‘subscriber’ node.

type ros2 topic list You can see/int32_subscriber topic name.

type ros2 node info /subscriber You can query the functions and message types of nodes.

type ros2 topic echo /int32_subscriber Print out /int32_subscriber messages.

Open a new terminal type

source /opt/ros/foxy/setup.bash

ros2 topic pub /int32_subscriber std_msgs/msg/Int32 "{data: 1234}"

The agent starts publishing messages under/int32_subscriber topics, and you can see the nodes that subscribe to /int32_subscriber topic printing out.

data: 1234
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data: 1234
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data: 1234
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data: 1234
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data: 1234
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