IMU Data Printing

This tutorial uses Ubuntu 20.04 and ROS1 version Noetic as an example.

1. Connecting the Device

Connect the IMU attitude sensor to the host controller's USB port using a Type-C cable.

If using a virtual machine, refer to the following steps:

Virtual machine displays a pop-up window

Virtual machine does not display a pop-up window

2. Binding Device ID

2.1 Device Viewing Commands

View Device ID

lsusb

View Device Number

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ll /dev/ttyU*

2.2 Establishing Port Mapping

Enter the rules.d directory

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cd /etc/udev/rules.d/

Create a new file named myimu.rules and write the following content:

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sudo gedit myimu.rules

If it prompts that the gedit command cannot be found, run:

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sudo apt install gedit -y

Write the following content:

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KERNEL=="ttyUSB*", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", MODE:="0777", SYMLINK+="myimu"

Save and exit to apply the rule

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sudo udevadm trigger
sudo service udev reload
sudo service udev restart

Replug and replug the USB device. Done!

Introduction to Rule File Syntax

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KERNEL=="ttyUSB*", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", MODE:="0777", SYMLINK+="myimu"
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Analysis

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KERNEL # The device name matching the event
ATTR{filename} # The sysfs attribute of the device matching the event. ... idVendor # Manufacturer ID
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idProduct # Product ID
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SYMLINK # Creates a symbolic link for the device file under /dev/. This gives the device an alias.
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MODE # Sets permissions for the device.

2.3 Verification and Viewing

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ll /dev/my*

3. Installing the Driver Library

3.1 Downloading the File

The latest version of the driver library, named YbImuLib.zip, is provided in the data folder.

3.2 Installing the Driver Library

Copy the YbImuLib.zip file to the virtual machine.

Unzip

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unzip YbImuLib.zip 

Install Library

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cd YbImuLib

Run the installation command. If you see the installation version number at the end, the installation was successful. This command will overwrite any previously installed Rosmaster_Lib driver library.

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sudo python3 setup.py install

Install other necessary libraries

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sudo pip3 install pyserial
sudo pip3 install smbus2

4. IMU ROS environment configuration

4.1 Creating and compiling a workspace

Open the command terminal, return to the home directory, and run the following command:

Create a new workspace

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mkdir ros_imu_ws
cd ros_imu_ws
mkdir src
cd src
catkin_init_workspace

Copy the imu_ros1_device folder to the ~/ros_imu_ws/src directory

Compile

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cd ~/ros_imu_ws
catkin_make

After successful compilation, add the workspace path to .bashrc:

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sudo gedit ~/.bashrc

Copy the following content to the end of the file:

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source ~/ros_imu_ws/devel/setup.bash

Save and exit, update environment variables

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source  ~/.bashrc

4.2 Printing IMU Data

Open a terminal and start roscore

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roscore

Open another terminal and start the IMU node

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rosrun imu_ros1_device ybimu_driver.py

Open a second terminal and check the IMU topic

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rostopic list

Print the data for the /imu/data_raw topic

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rostopic echo /imu/data_raw

Open a new third terminal and print the topic data /imu/mag

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rostopic echo /imu/mag 

5. Raspberry Pi 5, RDK X5 series, Jetson series

Note: Steps 2. Binding device ID and 3. Installing driver libraries need to be completed beforehand.

5.1 Installing Docker

1. Docker official website installation reference manual: https://docs.docker.com/engine/install/ubuntu/
2. Use the following command for one-click installation:

Note: Docker installation failure is normal. You can try multiple times, or install it using a proxy. You need to search online for instructions on using a proxy.

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curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun

3. Check the Docker version

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sudo docker version

5.2 Importing the Docker Image

Upload all files in the ROS1_noetic folder within the Docker image folder in the attached folder to the main controller. Then run the following command to import it.

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docker load -i ros1_imu.tar

Note: Importing the image takes a long time, please be patient. It is recommended to use a TF card of 64GB or more with at least 30GB of free space to avoid insufficient space causing import failure.

5.3 Start the Docker Image

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sh ros1_noetic.sh

5.4 Print IMU Data

Start roscore

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roscore

Open a second terminal and view the container ID

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docker ps

Based on the container ID displayed above, change the container ID in the following command to the actual displayed ID, allowing multiple terminals to access the same Docker container

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docker exec -it container_id /bin/bash

Start the IMU node

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rosrun imu_ros1_device ybimu_driver.py

Open a third terminal, refer to the second terminal for multi-terminal access to the same Docker container.

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docker ps

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docker exec -it container_id /bin/bash
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Check IMU topics

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rostopic list

Print /imu/data_raw topic data

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rostopic echo /imu/data_raw

Print /imu/mag topic data

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rostopic echo /imu/mag