Hi-Link HLK-LD303-24Gr User manual

HLK-LD303-24G USER MANUAL
HLK-LD303-24Gr Radar Module User Manual
V1.3.3
Shenzhen Hi-Link Electronic Co., Ltd.

HLK-LD303-24G USER MANUAL
1
CONTENTS
Summary....................................................................................................................................1
1、Appearance and interface.....................................................................................................2
2、Technical parameters.......................................................................................................... 3
3、Data protocol.......................................................................................................................3
4、Application occasions......................................................................................................... 5
5、Mechnical dimensions........................................................................................................ 6
6、Precautions..........................................................................................................................7
Appendix....................................................................................................................................8

HLK-LD303-24G USER MANUAL
2
Summary
HLK-LD303-24G is a radar module used to detect the distance between a sensor and a non-stationary target
1、Appearance and interface
(Module digital surface)
(Antennal Surface)
The interface is a 4-pin lock terminal with a pitch of 1.25mm. The wire sequence is as follows:
No.
PCBA silk screen
Function
1
5V
+5V input
2
GND
Ground wire
3
RX
Serial port receving
4
TX
Serial port sending
*The current terminal wiring is shown in the figure below：

3
HLK-LD303-24G USER MANUAL
2 、 Technical parameters
Parameters
Explanation
Trasmit frequency
24.00~24.250GHz
Antenna style
Horizontal angle 43°/vertical angle 116°
Working current
79mA(5V)
Working voltage
DC5V~12V
Working temperature
-20~+60℃
Data interface
TTL serial port
Data format
115200，8，n，1
Response time
≥60mS
Level output
Reserved
Detection range
10~350cm
Detection dead zone
10cm
Detection accuracy
5cm
Product size
39*29mm
3、Data protocol
Communication configuration：
TTL serial port, the default baud rate is 115200, the data bit is 8, the stop bit is 1, and there is no
check bit.
Fixed query command (HEX): 55 5A 02 D3 84
The module defaults to query mode, sending fixed hexadecimal query commands, and the
module reports distance and other data after successful reception.
Communication format：

Uplink data (module sending)
Word
threshold
Frame
header
length
Add
Distance
Reserve
Situation
Signal
strength
Fretting
Radar
off
check
Number
of bytes
2
1
1
2
1
1
2
1
1
1
content
55A5
0A
D3
XX
XX
X
X
X
X
X
XX

4
HLK-LD303-24G USER MANUAL
Description：
Report data information, the reporting interval can be set to 60ms~1s, the default is 60ms, the threshold
analysis of each word is as follows：
Length: the number of bytes except the frame header and check byte, 0x0A, fixed byte
Address: 0xD3, fixed byte
Distance: Unit: cm, occupies 2 bytes, high order first
Reserved: 1 byte, value 0x00, fixed byte
Status: Target presence or absence. Occupies 1 byte, 0: No one 1: Someone
Signal strength: unit: k, occupies 2 bytes, high order first
Fretting: value 0 or 1, 0: no fretting, 1: with fretting
Radar off: Whether the radar is off, the value is 0 or 1, 0: not off 1: off
Check: Sum check, all bytes except check word threshold are sum, and the lower 8 bits are taken,
occupying 1 byte
eg：
55 A5 0A D3 00 58 00 01 01 4C 01 01 7F
Available: There are people in the detection area, the distance is 88cm, and the signal strength is 332 k
Downlink data (received by the module)
Word
threshold
Frame
header
Add
Comman
d number
Command
parameters
Check
End of
frame
Byte length
2
1
1
2
1
2
Content
BAAB
00
E5
XX
0
0
55BB
Explanation：
 Frame header: fixed 2 bytes, 0xBAAB
 Address: 0x00, fixed byte

Command number: The command number for setting the maximum detection distance, 0xE5, fixed byte
 Command parameters: set the maximum detection distance, occupying 2 bytes, high order first

5
HLK-LD303-24G USER MANUAL

Check: no check, 0x00, fixed byte
 End of frame: fixed 2 bytes, 0x55BB
 Return of successful setting: 0D 0A 77 72 69 74 65 20 6F 6B 0D 0A
That is, the ASII code "Enter + write ok + Enter"
4 、 Application occasions
Intelligent toilet, detecting people
approaching different distances, assisting the
toilet system to perform operations such as
opening the lid, turning on the lights, flushing,
and heating
Inductive door, detect people within the set
distance to realize automatic opening and
closing of the door
Automatic escalator, it works normally when
detecting a person close to 1m, and enters a low power
consumption state when no one is overtime, assisting the
escalator to realize automatic induction

6
HLK-LD303-24G USER MANUAL
39.0
33.5
24.0
29.0
Φ3
Intelligent light control, to assist smart
homes to achieve the effect of "lights on when
people come, and lights off when people go"
5、Mechanical Dimensions
PCBA Schematic diagram：Unit mm
6、Precautions
a. Thismoduleonlydetectsrelativemovingtargetsinthedetectionarea,andcompletelystationarytargetsare notdetected.
Theoutputresultisinformationsuchasthedistance ofthenearesttargetinrelativemotion in thedetectionarea。
b. The module defaults to query mode (protocol 6). If you need to report continuously and automatically, just
change the protocol to 7. (Use the host computer to modify or directly send the command BAAB00F600070055BB)
c.Refer to the diagram of the relationship between the angle and the farthest working distance in the appendix
for the detection area
d. If the module is designed with a shell, the distance between the radar antenna surface and the shell surface is
6mm. The thickness of the shell is about 2~3mm. The shell material cannot use metal or metal-plated paint. It is
recommended to use PC, plastic, steel, etc.

7
HLK-LD303-24G USER MANUAL
Appendix:
Relationship between angle and farthest distance
Explanation：
Test target: human body
Installation: install horizontally respectively 、Vertical installation
Red broken line: the module is installed horizontally, with the module as the center of the circle, the vertical line
of the antenna surface is 0°, and each angle corresponds to the broken line of the farthest distance that can be detected
Blue fold line: the module is installed vertically, with the module as the center of the circle, the vertical line of the
antenna plane is 0°, and each angle corresponds to the fold line of the farthest distance that can be detected