Hi-Link HLK-LD2410C User manual

Page 1/ 19
Shenzhen Hi-Link Electronic Co., Ltd.
HLK-LD2410C
Human Presence Motion Module
User Manual
Version: V1.00 Revised date: 2022-11-7 Copyright by @ Hi-Link Electronic Co., Ltd.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 2/ 19
HLK-LD2410C
Content
1. Product introduction ..................................................................................................3
2. Product features and benefits ................................................................................... 4
2.1 Features .................................................................................................................. 4
2.2 Solution advantage ................................................................................................. 4
3. Application scenarios .................................................................................................5
4. Hardware description ................................................................................................ 6
4.1 Dimensions .............................................................................................................6
4.2 Pin definition .......................................................................................................... 7
5. Use and configuration................................................................................................8
5.1 Typical application circuit ..................................................................................... 8
5.2 The role of configuration parameters .................................................................... 8
5.3 Visual configuration tool description .................................................................... 9
5.4 Mounting method and sensing range ...................................................................10
5.5 Installation conditions .......................................................................................... 12
6. Bluetooth instructions ..............................................................................................13
6.1 Install software ..................................................................................................... 13
6.2 Instructions ........................................................................................................... 13
6.3 Bluetooth password ..............................................................................................13
6.4 OTA upgrade ........................................................................................................ 13
6.5 Bluetooth communication protocol ..................................................................... 13
6.6 Turn on bluetooth again ....................................................................................... 16
7. Performance and electrical parameters ................................................................ 17
8. Radome design guidelines ....................................................................................... 18
8.1 Effects of radomes on mm wave sensor performance.........................................18
8.2 Radome design principles .................................................................................... 18
8.3 Common materials ............................................................................................... 18
9. Revision records ....................................................................................................... 19
10. Technical support and contact ..............................................................................19

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 3/ 19
HLK-LD2410C
1. Product Introduction
LD2410C is a high-sensitivity 24GHz human presence status sensing module developed by Hi-
link Electronics. Its working principle is to use FMCW frequency-modulated continuous wave to
detect human targets in the set space. Combined with radar signal processing and accurate human
body sensing algorithms, it realizes high-sensitivity human presence status sensing, and can identify
human bodies in motion and stationary states. And auxiliary information such as the distance of the
target can be calculated.
This product is mainly used in indoor scenes to sense whether there is a moving or micro-
moving human body in the area, and output the detection results in real time. The farthest sensing
distance can reach 5 meters, and the distance resolution is 0.75m. Provides a visual configuration
tool, which can easily configure the sensing distance range, sensing sensitivity in different intervals
and unmanned delay time, etc., to adapt to different specific application needs.
Support GPIO and UART output, plug and play, and can be flexibly applied to different smart
scenarios and terminal products.
Figure 1 Diagram of usage

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 4/ 19
HLK-LD2410C
2. Product features and benefits
2.1 Features
Plug and play, easy assembly
The longest sensing distance is up to 5 meters
Large detection angle, coverage up to ±60 degrees
Accurate identification within the interval, support the division of the sensing range, and shield the
interference outside the interval
Multi-level intelligent parameter adjustment can be realized through Bluetooth or serial port to
meet the needs of scene changes
Visual debugging and configuration tools
Small and simple, the minimum size is only 16mmx22mm
Supports various installation methods such as ceiling hanging and wall hanging
24GHz ISM band, can be certified by FCC and CE spectrum regulations
The ultimate cost-effective choice
2.2 Solution advantage
The LD2410C human body sensing module adopts 24GHz millimeter wave radar sensor
technology. Compared with other solutions, it has obvious advantages in human body sensing
applications:
1. In addition to being sensitive to moving human bodies, it can also sensitively sense static,
micro-moving, sitting and lying human bodies that cannot be identified by traditional solutions;
2. It has good environmental adaptability, and the sensing effect is not affected by the
surrounding environment such as temperature, brightness, humidity and light fluctuations;
3. It has good shell penetration and can be hidden in the shell to work without opening holes on
the surface of the product, which improves the aesthetics of the product;
4. It can flexibly configure the farthest sensing distance and the sensitivity on each distance door
to achieve flexible and fine personalized configuration;
5. With the Bluetooth function, you can directly use the APP to debug the radar parameters
without catching the serial port.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 5/ 19
HLK-LD2410C
Infrared
solution
Visual
solution
Ultrasonic
wave
Lidar
Millimeter
wave
radar
Application flexibility
Resistance to environmental
influences
(weather light, etc.)
Detection speed
Detection accuracy
Resolution
Directionality
Detection distance
Ability to penetrate material
Dimension
Cost
Good Common Weak
Figure 2 Comparison of millimeter wave radar scheme and other schemes
3. Application scenarios
The LD2410C human body sensing module can detect and identify the human body in motion,
fretting, standing, sitting and lying down. It supports multi-level parameter adjustment and can be
widely used in various AIoT scenarios. The common types are as follows:
Human body sensor light control
It senses whether there is someone in the space, and automatically controls lights, such as lighting
equipment in public places, various sensor lights, bulb lights, etc.
Human body induction wake-up of advertising screen and other equipment
Automatically turn on when people come, and automatically sleep when no one comes to save power,
information delivery is more accurate and efficient.
Life safety protection
UV lamp work protection, to prevent the UV lamp from being turned on when there are people
around and causing personal injury;
Automatic detection and alarm of dangerous places to prevent people from entering specific high-
risk spaces, such as high-risk places entered by personnel from coal mine blasting.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 6/ 19
HLK-LD2410C
Smart home appliances
When there is no one in the room for a long time, the TV, air conditioner and other electrical
appliances are automatically turned off, saving energy and safety.
Intelligent security
Detection and identification of people intruding, staying, etc. within the specified range.
Figure 3 Application Scenario
4. Hardware description
4.1 Dimensions
Figure 4 Module Real Image

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 7/ 19
HLK-LD2410C
Figure 5 Module Dimensions
Module size: 16mmx22mm, 5 pin holes are reserved in the hardware
(the factory default does not match the pins)
The pin hole diameter is 0.9mm, and the pin spacing is 2.54mm.
4.2 Pin definition
Figure 6 Module pin definition diagram
Pin
Symbol
Items
Function
1
UART_Tx
Serial Tx
Serial Tx pin
2
UART_Rx
Serial Rx
Serial Rx pin
3
OUT
Target status
output
Human presence detected:
output high level
No human presence: output
low level
4
GND
Power ground
Power ground
5
VCC
Power Input
Power input 5~12V（advise 5V）

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 8/ 19
HLK-LD2410C
Table 1 Pin Definition Table
5. Use and configuration
5.1 Typical application circuit
The LD2410C module directly outputs the detected target state through an IO pin (someone is
high, no one is low), and it can also output the detection result data through the serial port according
to the specified protocol. The serial port output data includes: Target status and distance auxiliary
information, etc., users can use it flexibly according to specific application scenarios.
The power supply voltage of the module is 5V, and the power supply capacity of the input
power supply is required to be greater than 200mA.
The module IO output level is 3.3V. The default baud rate of the serial port is 256000, 1 stop bit,
and no parity bit.
5.2 The role of configuration parameters
The user can modify the configuration parameters of the module through the serial port of the
LD2410C to adapt to different application requirements, and the configuration content will not be
lost when the power is turned off.
The configurable parameters include the following:
farthest detection distance
Set the farthest detectable distance, only human targets that appear within this farthest distance
will be detected and output the result.
Set in units of distance gates, and each distance gate is 0.75m.
Including the farthest door for motion detection and the farthest door for static detection, the
setting range is 1 to 8. For example, if the farthest door is set to 2, only if there is a human body
within 1.5m will it effectively detect and output the result.
Sensitivity
Only when the detected target energy value (range 0~100) is greater than the sensitivity value will
it be determined that the target exists, otherwise it will be ignored.
The sensitivity value can be set from 0 to 100. The sensitivity of each range gate can be
independently set, so that the detection in different distance ranges can be precisely adjusted, local
accurate detection or filtering of interference sources in specific areas.
In addition, if the sensitivity of a certain distance gate is set to 100, the effect of not recognizing
the target under the distance gate can be achieved. For example, if the sensitivity of distance gate 3
and distance gate 4 is set to 20, and the sensitivity of other distance gates is set to 100, it is possible
to detect only the human body within the range of 2.25-3.75m from the distance module.
no-one duration
When the radar outputs the result from man to no man, it will report man for a period of time. If
there is no man in the radar test range during this time period, the radar will report no man; if the
radar detects man during this time period, it will be refreshed again. This time, in seconds. It is
equivalent to the unmanned delay time. After the person leaves, the output state will be unmanned
only after the person has left the system for more than this duration.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 9/ 19
HLK-LD2410C
5.3 Visual configuration tool description
In order to facilitate the user to test and configure the module quickly and efficiently, a PC
configuration tool is provided. The user can use this tool software to connect the serial port of the
module, read and configure the parameters of the module, and receive the detection results reported
by the module. Data, and real-time visual display, which greatly facilitates the use of users.
How to use the host computer tool:
1. Use the USB to serial port tool to connect the module serial port correctly;
2. Select the corresponding serial port number in the host computer tool, set the baud rate to
256000, select the engineering mode, and click to connect the device;
3. After the connection is successful, click the Start button, and the graphical interface on the right
will display the test results and data;
4. After connecting, when the start button is not clicked, or click stop after starting, the mode
parameter information can be read or set;
Note: The parameters cannot be read and configured after clicking start, and configuration can only
be performed after stopping.
The interface and common functions of the host computer tool are as follows:

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 10 / 19
HLK-LD2410C
5.4 Mounting method and sensing range
Figure 7 Schematic diagram of ceiling-mounted installation
(distance unit: meters, angle unit: degrees)
Figure 8 Schematic diagram of the detection range (the ceiling height is 3 meters)
Radar
Ceiling
High 2.6~3m

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 11 / 19
HLK-LD2410C
Radar
Wall
5m
High 1.5~2m
(distance unit: meters, angle unit: degrees)
Figure 9 Schematic diagram of wall-mounted installation
Figure 10 Schematic diagram of the detection range (the height of the wall is 1.5 meters)

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 12 / 19
HLK-LD2410C
5.5 Installation conditions
Confirm the minimum installation clearance
If the radar needs to be installed with a casing, the casing must have good wave-transmitting
properties at 24GHz, and cannot contain metal materials or materials that have a shielding effect on
electromagnetic waves.
Installation environment requirements
This product needs to be installed in a suitable environment. If it is used in the following
environments, the detection effect will be affected:
• There are non-human objects that are continuously moving in the sensing area, such as animals,
continuously swinging curtains, large green plants facing the air outlet, etc.
• There is a large area of strong reflectors in the sensing area, and the strong reflectors will cause
interference to the radar antenna.
• When installing on the wall, external interference factors such as air conditioners and electric
fans on the top of the room need to be considered.
Precautions during installation
• Try to ensure that the radar antenna is facing the area to be detected, and the surrounding area of
the antenna is open and unobstructed
• To ensure that the installation position of the sensor is firm and stable, the shaking of the radar
itself will affect the detection effect.
• To ensure there is no movement or vibration on the back of the radar. Due to the penetrating
nature of radar waves, the back lobe of the antenna signal may detect moving objects behind the
radar. A metal shield or metal backplane can be used to shield the radar back lobe and reduce the
impact of objects on the back of the radar
• The theoretical distance accuracy of radar is the result obtained through special algorithm
processing on the basis of the physical resolution of 0.75 meters. Due to the difference in the size,
state, and RCS of the target, the target distance accuracy will fluctuate; at the same time, the longest
distance will also fluctuate slightly.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 13 / 19
HLK-LD2410C
6. Bluetooth instructions
6.1 Install software
Currently the APP supports Android and IOS platforms, you can download it from this link:
https://www.pgyer.com/Lq8p (Android) You can also go to major app stores to search for
"HLKRadarTools" and install it.
App
6.2 Instructions
Open the app, and the app searches for nearby radar devices. The broadcast name of the device is
"HLK-LD2410B_xxxx" (xxxx is the last four digits of the mac address). After the module is
successfully connected, you can view the radar information, or debug and save the parameters.
The use distance of the APP should not exceed the Bluetooth signal range (within 4 meters).
①Search for Bluetooth ②View parameters ③Modify radar parameters
The process of modifying the radar parameters of the Bluetooth APP is the same as that of the PC
host computer tool.
6.3 Bluetooth password
You must enter a password to control the APP for the first connection. The default password is HiLink,
which can be modified in Parameter Settings -> Control Password. The password is fixed at 6 bytes.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 14 / 19
HLK-LD2410C
Note: Only V1.07.22091516 or newer version supports password function
6.4 OTA Upgrade
When the firmware of the device has been updated, the word “upgradeable” will appear on the
firmware version, long press the version number to enter the upgrade interface; only or
newer versions support the upgrade.
Long press the red circle to enter the upgrade Enter OTA upgrade

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 15 / 19
HLK-LD2410C
During Upgrading
The overall upgrade time takes 1~3 minutes. The upgrade must be performed from
the module, otherwise the upgrade will fail if the Bluetooth signal is poor.
Do not power off or restart the module before the upgrade is completed, and do not forcibly exit the
APP, otherwise the upgrade will fail. If the upgrade fails, the 2410C's radar program will be disabled and
radar detection will not be possible.
If the device upgrade fails, please restart the device and reconnect the APP, and a "waiting for
upgrade" prompt will appear on the device list:

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 16 / 19
HLK-LD2410C
Waiting for upgrading Upgraded successfully
Click the device to be upgraded to re-upgrade, and the radar function can be restored only after the
upgrade is successful.
6.5 Bluetooth communication protocol
2410C acts as a slave side, only allowed to be connected by one master.
Feature UUID
Operation authority
Function definition
0000fff1-0000-1000-8000-00805f9b34fb
Read/Notify
Module send,
APP receive
0000fff2-0000-1000-8000-00805f9b34fb
Write Without Response
APP send,
module receive
When the app and 2410C Bluetooth connection and password verification are successful, the module
will start the transparent transmission of radar data. The data transmitted by Bluetooth is exactly the
same as the serial port protocol, please refer to the "LD2410C Serial Port Communication Protocol.
pdf" document.
If the App is successfully connected, it will send a Bluetooth password to the module for verification.
Only when the password is correct, the module will start to transparently transmit data. For details, see
the chapter Obtaining Bluetooth Permissions in "LD2410C Serial Communication Protocol.pdf".
6.6 Turn on bluetooth again
The Bluetooth function of LD2410C is enabled by default, and Bluetooth can be turned off or
turned on through the serial port protocol (see LD2410C serial port communication protocol.pdf). If
the bluetooth has been turned off, or the serial port cannot be used, the bluetooth can be turned on
again after the module is powered off and then powered on for more than 5 times within 2~3s.

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 17 / 19
HLK-LD2410C
7. Performance and electrical parameters
Operating frequency
24GHz~ 24.25GHz
Compliant with FCC, CE,
non-commission certification standards
Operating Voltage
DC 5V, power supply capacity>200mA
Average operating current
79 mA
Modulation
FMCW
Interface
A GPIO, IO level 3.3V
A UART
Target application
Human presence sensor
Detection distance
0.75m ~ 6m, adjustable
Detection angle
±60 °
Distance resolution
0.75m
Sweep Bandwidth
250MHz
Compliant with FCC, CE,
non-commission certification standards
Ambient temperature
-40 ~ 85℃
Dimensions
7mm x 35 mm
Table 2 Performance and electrical parameters table
Figure 11 Measured data of module working current

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 18 / 19
HLK-LD2410C
8. Radome design guidelines
8.1 Effects of radomes on mm wave sensor performance
• Radar waves are reflected on the radome boundary
• Losses in total radar radiated or received power
• The reflected wave enters the receiving channel, affecting the isolation between the
transmitting and receiving channels
• Reflections may degrade the standing wave of the antenna, further affecting the antenna gain
• Radar waves will suffer loss when propagated in the medium. In theory, the higher the
frequency, the greater the loss will be
• Electromagnetic waves undergo a certain degree of refraction as they pass through a medium
• Affects the antenna's radiation pattern, which in turn affects the sensor's coverage
8.2 Radome design principles
8.3 Common materials
• Understand the material and electrical characteristics of the radome before designing
• The table on the right is for reference only, the actual value should be confirmed with the
supplier
• Height H from the antenna to the inner surface of the radome
• If there is enough space, it is preferred to recommend 1 times or 1.5 times the wavelength
• For example, 12.4 or 18.6mm is recommended for 24.125GHz
• Error control: ±1.2mm

Shenzhen Hi-Link Electronic Co., Ltd. Manual
Page 19 / 19
HLK-LD2410C
• Radome thickness D
• Recommended half wavelength, error control±20%
• If the thickness requirement of half wavelength cannot be met
• It is recommended to use low materials
• Thickness recommended 1/8 wavelength or thinner
• Influence of heterogeneous materials or multi-layer composite materials on radar performance,
it is recommended to make experimental adjustments during design
Table 3 Common Material Properties of Radomes
9. Revision records
Date
Version
Modify the content
2022-11-7
1.00
Initial version
10. Technical support and contact
Shenzhen Hi-Link Electronic Co.,Ltd
Phone：[phone]
Website：www.hlktech.net