YDLIDAR X4 User manual

X4
USER MANUAL
Shenzhen EAI Technology Co.,Ltd.
DOC #:01.13.000002
www.ydlidar.com

Copyright 2015-2021 EAI
CONTENTS
1YDLIDAR X4 LIDAR DEVELOPMENT KIT ....................................... 1
1.1 Development Kit ................................................................................. 1
2USAGE UNDER WINDOWS.............................................................. 2
2.1 Device Connection .............................................................................2
2.2 Driver Installation ...............................................................................3
2.3 Evaluation Software Usage................................................................5
2.3.1 Start Scanning...................................................................................................6
2.3.2 Data Storage......................................................................................................6
2.3.3 Display Mean and Standard Deviation............................................................6
2.3.4 Play and Record................................................................................................7
2.3.5 Debug.................................................................................................................8
2.3.6 Filter...................................................................................................................8
3LINUX ROS OPERATION.................................................................. 9
3.1 Device Connection .............................................................................9
3.2 Compile and Install YDlidar-SDK.......................................................9
3.3 ROS Driver Installation.......................................................................9
3.4 Run the ydlidar_ros_driver .............................................................. 10
3.5 RVIZ View Scan Results................................................................... 10
3.6 Modify Scan Angle............................................................................11
4CAUTION......................................................................................... 12
4.1 Ambient Temperature....................................................................... 12
4.2 Ambient Lighting .............................................................................. 12
4.3 Power Supply.................................................................................... 13
5REVISE ............................................................................................ 14

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1YDLIDAR X4 LIDAR DEVELOPMENT KIT
The development kit of YDLIDAR X4 lidar (hereinafter referred to as X4) is an
accessory tool provided for performance evaluation and early development of the X4.
Through the X4 development kit, and with the evaluation software, users can observe point
cloud data scanned by X4 on your environment or development on the SDK.
1.1 Development Kit
The X4 development kit has the following components：
FIG 1 YDLIDAR X4 DEVELOPMENT KIT
CHART 1 YDLIDAR TG SERIES LIDAR DEVELOPMENT KIT DESCRIPTION
Item
Qty.
Description
X4 lidar
1
Standard version of the X4 Lidar. The X4 has an integrated motor
drive for despin control and motor control.
USB Type-C
Cable
1
Use with USB adapter board to connect X4 and PC. USB cable is
both a power supply cable and a data cable.
USB Adapter
Board
1
Realize the function of USB to UART, which is convenient for the
fast interconnection between X4 and PC. Serial port DTR signal to
control X4 motor rotation and stop. In addition, a Micro USB
power interface (PWR) for auxiliary power supply is provided.
Note: USB Adapter board has two USB TYPE C interface：USB_DATA、USB_PWR.
USB_DATA: Data powered interface. In most cases, this interface can be used to meet power and
communication requirements.
USB_PWR: Auxiliary power supply interface. The USB interface of some development platforms
has weak current drive capability. At this time, auxiliary power supply can be used.
X4 Lidar
USB Type-C Cable
USB Adapter Board

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2USAGE UNDER WINDOWS
2.1 Device Connection
When evaluating and developing X4 under windows, you need to interconnect X4 and
PC. The specific process is as follows:
FIG 2 YDLIDAR X4 DEVICE CONNECTION STEP 1
FIG 3 YDLIDAR X4 DEVICE CONNECTION STEP 2
Connect the adapter board with X4 first, then connect the USB cable to the USB port of
the adapter board and the PC. Note that the Type-C interface of the USB cable is
connected to the USB_DATA of the USB adapter board, and the idle mode is used after X4
is powered on. The motor does not rotate.
The drive current of USB interface of some development platforms or PC is not
sufficient. X4 need to be connected to the auxiliary power supply of +5V, otherwise the lidar
will be abnormal.

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FIG 4 YDLIDAR X4 AUXILIARY POWER SUPPLY
2.2 Driver Installation
To evaluate and develop the X4 under Windows, you need to install the serial port
driver of the USB adapter board. The USB adapter board of this kit adopts CP2102 chip to
realize serial port (UART) to USB signal conversion. Its driver can be downloaded from our
official website or downloaded from the official website of Silicon Labs.
https://www.ydlidar.com/dowfile.html?id=97
http://cn.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
After decompressing the driver package, run the CP2102's Windows driver installation
file (exe file under CP210x_VCP_Windows). Please select the 32-bit version (x86) or 64-bit
version (x64) installation program according to the version of the windows operating
system.
FIG 5 YDLIDAR X4 DRIVER VERSION SELECTION
Double-click the exe file and follow the prompts to install it.
Development
Platform
5V Power
Supply

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FIG 6 YDLIDAR X4 DRIVER INSTALLING
After the installation is complete, you can right-click on [My Computer] and select
[Properties]. On the open [System] screen, select [Device Manager] from the left menu to
access the [Device Manager].
Expand [Port] to see the serial port name corresponding to the identified USB adapter,
that is, the driver installation is successful. The following figure shows COM3. (Note that the
port must be checked in case of X4 and PC interconnection).
FIG 7 YDLIDAR X4 DRIVER INSTALLATION CHECK

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2.3 Evaluation Software Usage
YDLIDAR provides Point Cloud Viewer, a point cloud data visualization software
LidarViewer for X4 real-time scanning. Users can intuitively observe the X4 scanning effect
chart. GDL real- time point cloud data and real-time scanning frequency are provided on
YDLIDAR. At the same time, the version information of X4 can be read, and you can save
the scanned data offline to an external file for further analysis
Before using the YDLIDAR software, make sure that the X4 USB adapter board serial
port driver is installed successfully, and interconnect the X4 with the USB port of the PC.
Run the evaluation software: LidarViewer.exe, select the corresponding serial port number
and model number. You could tick the square box to choose power off protection function.
Meanwhile, users could choose language and software type on the top right corner.
FIG 8 YDLIDAR X4 EVALUATION SOFTWARE
If the connection is correct, you will see the following screen：
FIG 9 POINTCLOUD VIEWER INTERFACE

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2.3.1 Start Scanning
Click to start scanning and display the environment point cloud, the upper left corner
displays the angle & distance information of the red line position (unit: mm). Click to stop
it. as shown below:
FIG 10 LIDAR SCANNING POINT CLOUD DISPLAY
2.3.2 Data Storage
During lidar scanning, click [File] in the main menu, select [Export to Excel], and save
point cloud data according to the prompts. Then the system will save the point cloud
information scanned in a circle in Excel format.
FIG 11 SAVE DATA
2.3.3 Display Mean and Standard Deviation
Click [Tools] in the main menu, then select [Mean And STD] - [View].
FIG 12 YDLIDAR G4 DISPLAY MEAN AND STANDARD DEVIATION

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Choose one according to your needs, move the mouse to the test position, right-click
the pop-up menu, and select [Lock Mouse Tracking].
FIG 13 LOCK MOUSE TRACKING
2.3.4 Play and Record
Click [Tools] in the main menu, then select [Record and Play].
FIG 14 RECORD AND PLAY
The main window is displayed as follows:
To record lidar data, click to start recording, and click to stop recording.
In non-scanning mode, click to start play.
The play process is as follows:

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FIG 15 PLAY PROCESS
2.3.5 Debug
Click [Tools] in the main menu, and then select [DebugON] to output the raw lidar data
to the "viewer_log.txt" and "viewer_log_err.txt" files.
FIG 16 START DEBUGGING
2.3.6 Filter
Click [Tools] in the main menu, and then select [Filter] to add lidar data filtering
algorithm.
FIG 17 FILTER SETTING
Note: For more functions of LidarViewer, please click [Help], select [More Information], and learn more
about how to use it.

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3LINUX ROS OPERATION
There are many Linux versions，this article only uses Ubuntu 18.04, Melodic version
ROS as an example.
SDK driver address：
https://github.com/YDLIDAR/YDLidar-SDK
ROS driver address：
https://github.com/YDLIDAR/ydlidar_ros_driver
3.1 Device Connection
Under Linux, the X4 and PC interconnect processes are consistent with those under
Windows. See Device Connection under Window.
3.2 Compile and Install YDlidar-SDK
YDLIDAR_ROS_DRIVER depends on the YDLIDAR-SDK library. If you have never
installed the ydlidar-SDK library, or it has expired, you must first install the YDlidar-SDK
library. If you have the latest version of ydlidar-SDK installed, please skip this step, Then
go to the next step.
3.3 ROS Driver Installation
1) Cloning GitHub's YDlidar ROS Driver Package:
2) Build the Ydlidar_ROS_Driver software package:
$ git clone https://github.com/YDLIDAR/YDLidar-SDK.git
$ cd YDLidar-SDK/build
$ cmake ..
$ make
$ sudo make install
$ git clone https://github.com/YDLIDAR/ydlidar_ros_driver.git
ydlidar_ws/src/ydlidar_ros_driver
$ cd ydlidar_ws
$ catkin_make

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3) Package environment Settings:
Note: Add permanent workspace environment variables. It will be very convenient if
ROS environment variables are automatically added to your bash session every time you
start a new shell:
4) Verify that your package path is set, echo the ROS_PACKAGE_PATH variable.
5) You should see something like this: /home/tony/ydlidar_ws/src:/opt/ros/melodic/share
Create Serial Port Alias [Optional]
Note: After completing the previous operation, re-insert the LIDAR again.
3.4 Run the ydlidar_ros_driver
Run ydlidar_ros_driver with startup file, as shown below:
3.5 RVIZ View Scan Results
Run the launch file and open rviz to view the X4 scan results, as shown in the figure
below:
Note: Take G4 as an example by default, if you use other types of lidar, you need to change lidar.launch
in lidar_view.launch file to the corresponding **.launch file. (If X4 lidar is used, it needs to be
changed to X4.launch)
$ source ./devel/setup.sh
$ echo "source ~/ydlidar_ws/devel/setup.bash" >> ~/.bashrc
$ source ~/.bashrc
$ echo $ROS_PACKAGE_PATH
$ chmod 0777 src/ydlidar_ros_driver/startup/*
$ sudo sh src/ydlidar_ros_driver/startup/initenv.sh
$ roslaunch ydlidar_ros_driver X4.launch
$ roslaunch ydlidar_ros_driver lidar_view.launch

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FIG 18 YDLIDAR X4 RVIZ
3.6 Modify Scan Angle
The scanning data seen by running the launch file is displayed by default with 360-
degree data. To modify the display range, you need to modify the configuration parameters
in the launch file. The specific operation is as follows:
1) Switch to the directory where the corresponding [launch file] is located, edit the file, and
its content is as shown in the figure:
FIG 19 X4.LAUNCH FILE
$ vim X4.launch

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Note: For more information about the file contents, please refer to:
https://github.com/YDLIDAR/ydlidar_ros_driver#configure-ydlidar_ros_driver-internal-
parameter
2) The X4 lidar coordinates follow the right-hand rule within ROS, with an angle range of
[-180, 180]. "angle_min" is the start angle, and "angle_max" is the endangle. The
specific scope needs to be modified according to actual use.
FIG 20 YDLIDAR X4 COORDINATES DEFINITION
4CAUTION
4.1 Ambient Temperature
When the working environment temperature of X4 is too high or too low, it will affect the
accuracy of the distance measuring system. It may also damage the structure of the
scanning system and reduce the life of the X4 lidar. Avoid use in high temperature (>50
degrees Celsius) and low temperature (<0 degrees Celsius) conditions.
4.2 Ambient Lighting
The ideal working environment of X4 is indoor, and the indoor environment light
(including no light) will not affect the work of X4. However, please avoid using strong light
sources (such as high-power lasers) to directly illuminate the X4 vision system.
If you need to use it outdoors, please avoid the X4's vision system directly facing the
sun, which may cause permanent damage to the vision system's photosensitive chip, which
will invalidate the range finding.
The X4 standard version will cause interference in the distance measurement under
the conditions of strong sunlight reflection outdoors, please pay attention to it.

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4.3 Power Supply
During the development process, since the drive current of the USB interface of each
platform or the USB interface of the computer may be too low to drive the X4, the external
power supply of the +5V to the X4 needs to be provided through the USB_PWR interface of
the USB interface board. It is not recommended to use mobile phone power bank because
the voltage ripple of power bank is too large.

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5REVISE
DATE
VERSION
CONTENT
2017-12-05
1.0
Composing a first draft
2018-01-22
1.1
Added auxiliary power connection method, document description,
configuration description, and power supply requirements
2018-04-03
1.2
Adapt to PointCloudViewer2.0 client
2021-08-02
1.3
Adapt LidarViewer client, update SDK, ROS tutorial