seeed studio R24BBD1 User manual

Table of Contents
Overview 3
1. Principle of operation 3
2. Hardware Design Considerations 4
2.1 The power supply can be designed with the following circuit in mind4
2.2 using the wiring diagram 5
3. Antenna and housing layout requirements 5
4. Static Protection 6
5. Functional disturbances 6
5.1 Unoccupied state, abnormal output occupied 6
5.2 Manned status, abnormal output unoccupied 7
6. Functions in detail 8
6.1 Function point descriptions 8
6.2 Description of the output of the body motion amplitude parameter 9
7. Description of the agreement 9
8. Communication commands and parameter definitions 10
8.1 Definition and description of the frame structure 10
8.2 Description of address assignment and data information 11

Overview
This manual primarily describes the practical application of the radar system and
the issues that should be addressed at each stage to minimize design costs,
increase product stability, and improve project efficiency.
This manual talks about the hardware circuit reference design, the radar antenna
and shell layout requirements, and the use of a multifunctional standard UART
protocol.
The radar is a self-contained space-sensing sensor consisting of an RF antenna,
a radar chip, and a high-frequency multi-core processor. To meet the diverse
needs of users, it is built on a stable, flexible, and superior algorithmic
architecture core. It can be connected to a remote or host computer so that the
status and detection data can be sent in various ways. It also has several groups
of GPIOs that allow the user to customize the development.
1. Principle of operation
The radar transmits a 24G band millimeter-wave signal, the measured target
reflection electromagnetic wave signal, demodulates the transmitted signal, and
then obtains echo demodulation signal data through amplification, filtering, ADC,
and other processes. The echo signal's amplitude, frequency, and phase are
decoded in the MCU unit, which ultimately enables the measurement of the
target parameters (breathing, motion, tiny motions, etc.).

2. Hardware Design Considerations
The standard voltage power supply and input current of the radar under normal
circumstances should be 4.9–6V and 200 mA, respectively. Power supply design,
power ripple ≤ 100mV.
2.1 The power supply can be designed with the following circuit in mind
Fig. 1
Fig. 2

2.2 using the wiring
diagram
Fig. 3 Schematic diagram of the radar module and peripheral connections
3. Antenna and housing layout requirements
PCBA: Mount the radar ≥1mm higher than the other devices.
Case: Keep 2-5mm between the radar antenna and other shell surfaces.
Case detection surface: To avoid coverage area performance, keep the non-metallic
case flat and straight to avoid bending.
Fig. 4 Schematic diagram of the radar module and peripheral connections

4. Electrostatic (ESD) protection
Radar modules contain electrostatic-sensitive circuits, so they risk electrostatic shocks.
Thus, it is essential to maintain proper electrostatic protection throughout the process of
transportation, storage, work, and handling. Avoid touching the radar module's antenna
surface and connector pins, but hold the corners. We recommend that you wear anti-
static gloves during the operation of the radar sensor.
5. Function interference item
5.1 Unoccupied state, abnormal output occupied
When the radar is in its normal state, it will accurately determine the existence of human
sitting or sleeping states and will output fall data, breathing information, vital signs, etc.
a. Radar scanning covers a large area. You can detect movement around the
doorway and the next door in the wooden wall.
Adjustment method: Reduce radar sensitivity; the radar has scene settings
b. When the radar is facing toward the air conditioner and fan when it is
operating
Adjustment method: Position the radar so it doesn't directly face the air
conditioner and fan
c. Object shaking caused by air conditioning wind
Adjustment method: Cotton and non-metallic items do not cause false
alarms. Metal items should be well-positioned to avoid interference.
d. If the radar is not fixed, vibration may cause false alarms. To prevent this
from occurring, support the radar in a fixed position to avoid vibrations and
shakes.
e. Occasional moving objects, such as pets, birds, or other animals.
Because of the high sensitivity of the radar's detection of micromotions,
this interference cannot be eliminated.
f. Power supply interference can interfere with judgment, resulting in
occasional errors.
Maintain a stable current power supply and minimize ripple.

5.2 Occupied status, abnormal output unoccupied
Radar can determine whether a human body exists by transmitting and receiving
electromagnetic waves. The closer the body is to the radar, the higher the accuracy is.
a. The human body is out of radar’s range.
Adjust the installation angle to fit the range of the radar.
Measurement range: the electromagnetic wave reflection area is different in
different environments, and the scanning area may be slightly different.
b. Output error due to metal shielding
Thick office desks and chairs and metallic seats. This will block electromagnetic
waves from penetrating and causing inaccurate judgments.
c. The difference in scanning angle.
When the radar fails to detect the body part (torso area), it can cause errors.
d. The radar’s sensitivity is too low
The radar can be adjusted in order to improve sensitivity.
6. Functions details
6.1 Function point descriptions
Functions
Status change time/function
explanation
DP1: occupied/unoccupied
No one to occupied, report within 0.5s
Manned to unoccupied, no status
output in 1-2 minutes or so
DP2: Some people are stationary /
Some people are active
Static dynamic switching, reporting
within 0.5 seconds
DP3: Someone close to the device
/ someone moving away from the
device / someone moving without
direction
Status output once every 2 seconds
DP4: Body movement amplitude
Data output once every 5 seconds

Functions
Status change time/function
explanation
parameter 0 - 100
Reference (description of output of
body motion amplitude parameters)
DP5: Sensitivity setting 1 - 10
steps
Default scene mode, adapted to 10
positions of adjustment
DP6: Scene modes (bed,
bathroom, hotel, bedroom, office,
default mode)
Adapted to different scenarios
according to the size of the area
DP7: No false alarm confirmation
prompt
DP8: Sleep parameter switch
Off by default, sleep function only
works when on
DP9: Bed entry/exit
Output status in 3S clock
DP10: Number of bed entries/exits
Count the number of times you
enter/leave bed in a day
DP11: Stationary dwell alarms
Outputs in three states, once every 10
minutes
DP12: Length of Sobriety
DP13: Length of light sleep
DP14: Length of deep sleep
DP15: Breathing rate
Normal number of breaths can be
tested
DP16: Breathing rate detection
signal
If there are factors such as distance,
range and other effects, output
breath-holding abnormalities, good
signals, abnormal movements,

Functions
Status change time/function
explanation
abnormal states of shortness of
breath
DP17: Sleep scoring (optional,
users can rate according to their
own way)
Combined day's sleep rating
6.2 Description of the output of the body motion amplitude parameter
Body movement amplitude parameters
0%
None
Environmental
unmanned
1%
Stationary (sleep)
Only breathing
without body
movement
2% - 30%
Micro-Movements
Only minor head or
limb movements
Movement
31% - 60%
Walking/fast body
movements
Slower body
movements
61% - 100%
Running/close range big
moves
Rapid body movement
7. Description of the agreement
This protocol is used for communications between a millimeter-wave sleep detection
radar and a host computer. The protocol outlines the radar’s workflow describes the
interface protocol's composition architecture and provides the commands and data
necessary for the relevant radar function. The serial port is defined as the following:
Interface level: TTL
Baud rate: 9600bps

Stop bits: 1
Data bits: 8
Parity: None
8. Communication commands and parameter definitions
8.1 Definition and description of the frame structure
Frame structure definition
Starting
Code
Length of data
Function
codes
Address
code 1
Address
code 2
Data
Check Code
0X55
Lenth_L
Lenth_H
Command
Address_1
Address_2
Data
Crc16_L
Crc16_H
1 Byte
1 Byte
1 Byte
1 Byte
1 Byte
1 Byte
n Byte
1 Byte
1 Byte
Starting
Code
Length
of data
Function
codes
Address
code 1
Address
code 2
Data
Check
Code
Frame structure description
a. Start code: 1 Byte, fixed to 0X55.
b. Data length: 2 Byte, low byte before, high byte after. Length = Data Length +
Function Code + Address Code 1 + Address Code 2 + Data + Checksum.
c. Function code: 1 Byte
Read command: 0X01
Write command: 0X02
Passive report command: 0X03
Active report command: 0X04
d. Address code:
Address code 1 indicates the functional classification.
The address code 2 indicates the specific function.
Refer to the address assignment and data information description.
e. Data: n Byte
f. Checksum: 2 Byte, low byte before, high byte after.
CRC16 checksum is used. Refer to Appendix 1 for reference codes

8.2 Description of address assignment and data information
24G Bio-aware radar interface content
Function Code
Address
code 1
Address code 2
Data
Notes
1
Read command
0x01
Marking
search
0x01
Device ID 0X01
2
Software version 0x02
3
Hardware version 0x03
4
Protocol version 0x04
5
Radar
Information
Search
0x03
Environmental status
0X05
6
Signs parameters 0x06
7
System
parameter
search
0x04
Threshold gear 0x0C
8
Scene setting 0x10
Forced into unoccupied
gear 0X12
9
Other
information
enquiries
0X05
Sleep detection
parameter switch 0X0D
Enquiry
Current sleep
detection
switch status

24G Bio-aware radar interface content
1
copy
order
0x02
System
parameters
0x04
Threshold
gear 0x0C
Enumeration range1~10
Corresponding
to1 2 3 4 5 6
7 8 9 10 gears
(default 7)
The higher the
gear, the more
sensitive it is
2
Scene
setting 0x10
Default mode 0x00
3
Area detection (top loading)
0x01
4
Bathroom (top mounted)
0x02
5
Bedroom (top loading) 0x03
6
Living room (top mounted)
0x04
7
Office (top loading) 0x05
8
Hotel (top loading) 0x06
Forced into
unoccupied
gear 0X12
No forced access to the
unoccupied function 0X00
10s 0X01
30s 0X02
1min 0X03
2min 0X04
5min 0X05
10min 0X06
30min 0X07
60min 0X08

24G Bio-aware radar interface content
9
Other
functions
0X05
Reboot
0X04
10
Sleep
function
switch 0x0D
Off 0x00
On 0x01
Start OTA
upgrade
0X08
4byte Integer data
(firmware package size)+
nbyte (software version
number)
Upgrade
package
transfer
0X09
Packet Offset (4byte) +
Packet (1024byte)
End of
upgrade
information
0X0A
Fixed characters 0X0F
24G Bio-aware radar interface content
1
Passive
reporting
of
orders
0x03
Reporting module
identification 0X01
Device ID 0x01
12 Byte data
2
Software version 0x02
10 Byte data
3
Hardware version 0x03
8 Byte data
4
Protocol version 0x04
8 Byte data

24G Bio-aware radar interface content
1
Passive
reporting
of orders
0x03
Upload
Radar Info
0x03
Environment status
0x05
Nobody 00 FF FF
2
Static 01 00 FF
3
Movement 01 01 01
4
Signs parameters 0x06
4 Byte Float data (see
Appendix 2)
5
Reporting
system
parameters
0X04
Threshold gear 0X0C
Current gear value
(0X01~0X0a)
6
Scene setting 0x10
Default mode 0x00
7
Area detection (top loading)
0x01
8
Bathroom (top mounted)
0x02
9
Bedroom (top loading) 0x03
10
Living room (top mounted)
0x04
11
Office (top loading) 0x05
12
Hotel (top loading) 0x06
Forced into unoccupied
gear 0X12
No forced access to the
unoccupied function 0X00
10s 0X01
30s 0X02
1min 0X03
2min 0X04
5min 0X05
10min 0X06
30min 0X07
60min 0X08

13
Other
functions
0X05
Sleep function switch
0x0D
Off 0x00
On 0x01
14
Start OTA upgrade 0X08
Failed 0X00
15
Success 0X01
16
Upgrade package
transfer 0X09
Fixed characters 0X0F
24G Bio-aware radar interface content
1
Proactive
reporting
of
commands
0X04
Report
radar
information
0x03
Environment
status 0x05
Unoccupied 00 FF FF
2
Someone is stationary
01 00 FF
3
U Some people
exercise 01 01 01
4
Motor signs
parameters
0X06
4Byte Float data
5
Approaching
away state
0x07
Fixed
characters
0x01
0x01
None
0x01
Approach
0x02
Far away
0x03
6
Report
other
information
0X05
Heartbeat
Pack 0X01
Unoccupied 00 FF FF
7
Someone is stationary
01 00 FF
8
Some people exercise
01 01 01

24G Bio-aware radar interface content
9
Abnormal
reset 0X02
0X0F
When the radar is
restarted or re-
powered, an
abnormal reset
command is
reported before
the initialisation
process begins
and a successful
initialisation
command is
reported.
This means that
the radar has
been initialized
successfully.
Start of normal
operations.
Initialisation
successful
0X0A
0X0F
24G Bio-aware radar interface content
1
Sleeping
radar
data
reporting
0x05
Breathing
parameters
0x01
Breathing rate
0x01
1Byte integer
data
Detection
signal 0x04
Breath-holding
abnormality
0x01
No 0X02
Normal 0x00

24G Bio-aware radar interface content
Movement
abnormalities
0X04
When large movements
of the person occur,
abnormal movements
are indicated, informing
the user that large
movements may affect
the radar's detection of
breathing
Shortness of
breath abnormal
0X05
2
Scenario
assessment
0x03
In/out of bed
0x07
Out of bed 0X00
3
In bed 0X01
None 0x02
Sleep switch off shows
none
4
Sleep state
assessment
Awake 0x00
5
Light sleep 0x01
6
Deep sleep 0x02
7
None 0x03
Sleep switch off shows
none
8
Duration
parameter
0x04
Duration of
wakefulness
0x01
4Byte integer
data
Unit min
Length of light
sleep 0x02
4Byte integer
data
Length of
deep sleep
0x03
4Byte integer
data

24G Bio-aware radar interface content
9
Sleep
quality
parameter
0x05
Sleep quality
score 0x01
1Byte integer
data
Heart rate
parameter
0x06
Heart rate
value 0x01
1Byte integer
data
Unit times/min
Description:
1. The read-write command is the command that is transmitted from the host
computer to the radar.
2. The reporting command is when the radar transmits information to the host
computer.
3. Human body sensitivity is 1-10 levels, and the default is 7. The higher the level,
the more sensitive it is.
Appendix 1: CRC check digit reference parsing codes