Hi-Link HLK-B20 User manual

Shenzhen Hi-Link Electronic Co., Ltd.
HLK-B20 User Manual
BLE 4.2 wireless module

Contents
1. Product description....................................................................................................................................... 1
1.1. Basic parameters................................................................................................................................ 1
2. Product Overview......................................................................................................................................... 2
2.1. Technical specifications.....................................................................................................................2
Table 2-1 Product Specifications...................................................................................................... 2
2.2. Hardware description......................................................................................................................... 2
2.3. Block diagram.................................................................................................................................... 3
2.4. Default pin function........................................................................................................................... 3
3. Test board description...................................................................................................................................4
3.1. Restore factory settings......................................................................................................................4
4. Function description......................................................................................................................................5
5. Serial port working state conversion.............................................................................................................5
6. Led light indication meaning........................................................................................................................ 6
7. Parameter configuration method................................................................................................................... 6
8. Serial port AT command configuration........................................................................................................ 6
8.1. AT instruction format.........................................................................................................................6
8.1.1. Ver...........................................................................................................................................7
8.1.2. Uart..........................................................................................................................................7
8.1.3. net_commit..............................................................................................................................7
8.1.4. Reconn.................................................................................................................................... 7
8.1.5. ble_status.................................................................................................................................8
8.1.6. ble_name................................................................................................................................. 8
8.1.7. default......................................................................................................................................8
8.1.8. Reboot..................................................................................................................................... 8
9. Configuration Tool Description.................................................................................................................... 9
10. Transparent transmission minimum system................................................................................................9
11. Bluetooth data transmission...................................................................................................................... 10
12. Reflow soldering temperature curve......................................................................................................... 12
Appendix A Document Revision History....................................................................................................... 13

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1. Product description
HLK-B20 is an new low-consumption Bluetooth BLE 4.2 control module made by Hi-Link. This
product is a Bluetooth-compliant module based on universal serial interface. It has built-in BLE 4.2
protocol stack, which can realize data conversion between user serial port and Bluetooth interface.
1.1. Basic parameters
High-speed ARM9E core MCU
2.4G/1T1R, BLE 4.2
160k programming space, 20KB RAM
Power supply voltage 0.9-3.6v
Ultra low supply voltage, low power consumption
Built-in crystal, high stability
Small chip package 4x4
Rich peripheral interface, SPI, I2C, ADC, UART, PWM, GPIO
Widely used in the Internet of Things
High-speed 10-bit multi-channel ADC with internal filtering
Easy to connect, fast speed

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2. Product Overview
2.1. Technical specifications
Table 2-1 Product Specifications
Transfer Protocol
Bluetooth standard : BLE 4.2
Supply voltage
0.9-3.6V
Air speed
1Mbps
Number of channels
40
Frequency Range
2400-2480MHZ
Transmit power
4DB
Receiving sensitivity
-96dbm
Received power
5.1ma
Transmit power
4.5ma
Antenna type
External /internal antenna
Other parameters
Status indicator
Status indication
Environmental standard
Operating temperature: -40-125℃
Working humidity: 10%-90%RH (Non-condensing)
Storage temp.: -40-90℃
Storage humidity: 5%-90%RH (Non-condensing)
Other performance
Band bandwidth optional: 1MHz
2.2. Hardware description
HLK-B20 dimension as below:(L*W)=16mm*25mm
Figure 1 HLK-B20 Dimension

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2.3. Block diagram
UART
GPIO
PWM
I2C
SPI
ADC
HLK-B20
3.3V
16MH
z
RAM(20K)
1 IPEX
Connector
Figure 2 HLK-B20 Module architecture diagram
2.4. Default pin function
No.
Network name
Type
Function description
Default features
1
RSTN
I
Chip enable, high efficiency
CPU reset
2
P07
I/O
P07,SPI_NSS,PWM5
GPIO,SPI,PWM
3
P14
I/O
P14,PWM4
GPIO,PWM
4
P10
I/O
P10,PWM0
GPIO,PWM
5
P11
I/O
P11,PWM1
GPIO,PWM
6
P12
I/O
P12,PWM2
GPIO,PWM
7
P13
I/O
P13,PWM3
GPIO,PWM
8
3V3
P
3.3V power supply
Power
9
P31
I/O
P31
GPIO
10
P32
I/O
P32
GPIO
11
P17
I/O
P17,uart2_rxd
GPIO,uart2
12
P16
I/O
P16, uart2_txd
GPIO,uart2
13
P34
I/O
P32
GPIO

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14
P33
I/O
P33
GPIO
15
GND
P
GND
GND
16
P02
I/O
P02,SCL
GPIO,I2C
17
P03
I/O
P03,SDA
GPIO,I2C
18
P04
I/O
P04,SPI_CLK
GPIO,SPI
19
P05
I/O
P05,SPI_MOSI
GPIO,SPI
20
P06
I/O
P06,SPI_MISO
GPIO,SPI
21
P01
I/O
Uart1_rxd
Uart1, Transparent transmission serial
port
22
P00
I/O
Uart1_txd
Uart1, Transparent transmission serial
port
3. Test board description
The test board is mainly used to test the data transmission function of the HLK-B20's Bluetooth and
serial ports.
Figure 3 HLK-B20 module test board
3.1. Restore factory settings
To ensure that all configuration procedures are correct, first reset the module to factory settings.
Modules that are already in factory mode can skip this step. Provide 5V (1000mA) power supply to
power on the module, wait for about 1 second, let the module start up. After the startup is completed,
pull down the ES0 (PIN5) pin for more than 6S. When the LED corresponding to the STA is always
on, it means that the module is restored the factory settings successfully, then release the ES0 pin,
the system will automatically restart. The system is already in factory mode after rebooting.
RST
HLK-B20
USB to serial
port
ES0

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4. Function description
The module function is mainly to realize the mutual conversion of Bluetooth data and serial data.
HLK-B20
SERIAL
BLE
COM1
MCU
Bluetooth
device
Figure 4 Serial to BLE mode
In this mode, the BLE Bluetooth device transmits the data to the HLK-B20 module via Bluetooth, and
the HLK-B20 module sends the received data from the serial port. When the serial port gets data, the HLK-
B20 sends the serial port data from the Bluetooth terminal to realize the conversion of serial data and
Bluetooth data. When the HLK-B20 has a Bluetooth device connected, the HLK-B20 will turn off the
broadcast of the Bluetooth name, and other Bluetooth devices will no longer be able to connect to the HLK-
B20.
5. Serial port working state conversion
The module defines the working state of the serial port as two modes: transparent transmission mode
and AT command mode.
Power on
Yes
No
Normal configur.?
Transparent
mode
1. ES0(PIN5) pin
AT
command
mode
1.at+reconn=0
Figure 5 . Serial port working state transition
After normal power-on, the module directly enters the transparent mode. If Bluetooth is not
connected, the data will not be sent out from Bluetooth. If Bluetooth is connected, the data will be
sent out from Bluetooth. In any state, keeping the ES0 pin low for longer than Tes and less than
Trst will immediately enter the AT command mode.

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>Tes
RESET <Trst
t
AT Command
Figure 6. RST Exit transparent mode
Notes: Tes=100ms, Trst=6s
6. Led light indication meaning
The status of the led connection module's P02 pin, corresponding to the sta led on the test board:
* Double flash: Bluetooth is not connected, and is in transparent mode
* Triple flash: AT command mode
* Long extinction or fast flash: Bluetooth is connected, it will flash quickly when there is transparent
data transmission
7. Parameter configuration method
The module configuration is mainly configured through the serial port AT command.To configure
parameters through the serial AT command, you need to let the module enter the AT command mode
first.The serial port configuration tool HLK-B20_CONFIG, that configures the module through the AT
command mode, through the parameters of each configuration combinations, provides a simple and
convenient configuration process.
8. Serial port AT command configuration
8.1. AT instruction format
In AT mode, system parameters can be configured through the AT command of
the serial port. The format of the instruction is as follows: at+[command]=[value]\r
Different return values of the module will be returned depending on the different
command.
Example: "at+ble_name=blename\r" sets the module broadcast address to blename.
Example: "at+ver=?\r" queries the module program version number.

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Command list as below:
ver
Module Version
uart
Serial port configuration
default
Restore factory setting
ble_name
Bluetooth name
net_commit
Submit configuration parameters
reconn
Restart the serial port service
ble_status
Bluetooth connection status
Reboot
Restart the system
8.1.1. Ver
Function
Firmware version query
Format
at+ver=？\r
Parameter
No
8.1.2. Uart
Function
Serial port configuration settings
Format
at+uart=<baud>, <data>, <parity>, <stop>\r
Parameter
Baud: Baud rate
Data: Data bit
Parity: Check Digit
Stop: Stop bit length
8.1.3. net_commit
Function
Submit network settings
Format
at+net_commit=< Net_commit >\r
Parameter
0:invalid
1:Submit
8.1.4. Reconn
Function
Restart the serial port conversion service
Format
at+ reconn =< reconn >\r
Parameter
0: invalid
1: Restart the serial port conversion service

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8.1.5. ble_status
Function
Query Bluetooth connection status
Format
at+ ble_status =?\r
Parameter
0: Not connected
1: Connected
8.1.6. ble_name
Function
Query Bluetooth connection status
Format
at+ ble_name =<blename>\r
Parameter
blename: Bluetooth name
8.1.7. default
Function
Restore factory setting
Format
at+ default =1\r
Parameter
No
8.1.8. Reboot
Function
Restart the system
Format
at+ reboot =1\r
Parameter
No

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9. Configuration Tool Description
Figure 7 Configuration tool
1: Command window to be sent
2: Serial port number selection
3: Bluetooth name setting
4: Serial port parameters
5: Serial port return command
6: Submit configuration
7: Query configuration
8: Enter transparent mode
9: Restore factory settings
10.Transparent transmission minimum system
Figure 8 Minimum system

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11. Bluetooth data transmission
Bluetooth data transmission is that after the Bluetooth connection is successful, the module will send
the data received from the Bluetooth by the serial port, and the data received from the module serial port
will be sent out by the Bluetooth.
The module Bluetooth function only supports Bluetooth 4.2.
Install the Bluetooth mobile phone test software HLK-BLE.apk, open the Bluetooth function of the
mobile phone, and then open the app, it will search for the Bluetooth name at the beginning of HLK-BLE_
on the app.
Figure 9 Bluetooth search list
Then select the last item
Figure 10 Bluetooth attribute list

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Then input the sent data in the send box, click Send, the data will be received on the serial port, and the
data sent by the serial port will be received on the app.
Figure 11 Bluetooth transmission test

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12. Reflow soldering temperature curve
When the module is over-fired, please strictly follow this temperature curve. If the temperature deviation of the reflow
soldering is too large, the module will be damaged!
Temperature setting (degrees Celsius)
Warm zone
1
2
3
4
5
6
7
8
Upper
temperature
zone
125
135
155
185
195
225
240
230
Lower
temperature
zone
125
135
155
185
195
225
240
230
Conveyor speed: 70.0 cm/min

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Appendix A Document Revision History
Version
number
Revision
Scope
Date
1.00 2019-4-15

2.2 List of applicable FCC rules
FCC Part 15.247
2.6 RF exposure considerations
This module certified that complies with RF exposure requirement under 5mm RF
distance.
2.8 Label and compliance information
FCC ID label on the final system must be labeled with “Contains FCC ID:
2AD56HLK-B20” or “Contains transmitter module FCC ID: 2AD56HLK-B20”.
2.9 Information on test modes and additional testing requirements
Contact ShenZhen HaiLingKe Electronic co.,Ltd will provide stand-alone modular
transmitter test mode. Additional testing and certification may be necessary when
multiple modules are used in a host.
2.10 Additional testing, Part 15 Subpart B disclaimer
To ensure compliance with all non-transmitter functions the host manufacturer is
responsible for ensuring compliance with the module(s) installed and fully
operational. For example, if a host was previously authorized as an unintentional
radiator under the Supplier’s Declaration of Conformity procedure without a
transmitter certified module and a module is added, the host manufacturer is
responsible for ensuring that the after the module is installed and operational the
host continues to be compliant with the Part 15B unintentional radiator
requirements. Since this may depend on the details of how the module is integrated
with the host, ShenZhen HaiLingKe Electronic co.,Ltd shall provide guidance to the
host manufacturer for compliance with the Part 15B requirements.

FCC Warning
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions:
(1) This device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
NOTE 1: This product has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This product generates, uses, and can radiate
radio frequency energy and, if not installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no guarantee that interference will not
occur in a particular installation. If this product does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and on, the user is encouraged to try
to correct the interference by one or more of the following measures:
üReorient or relocate the receiving antenna.
üIncrease the separation between the equipment and receiver.
üConnect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
üConsult the dealer or an experienced radio/TV technician for help.
NOTE 2: Any changes or modifications to this unit not expressly approved by the party
responsible for compliance could void the user's authority to operate the equipment.
FCC Radiation Exposure Statement:
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled
environment. End users must follow the specific operating instructions for satisfying RF exposure
compliance.
Note 1: This module certified that complies with RF exposure requirement under 5mm RF
distance. This transmitter must not be co-located or operating in conjunction with any other
antenna or transmitter.
Note 2: Any modifications made to the module will void the Grant of Certification, this module is
limited to OEM installation only and must not be sold to end-users, end-user has no manual
instructions to remove or install the device, only software or operating procedure shall be placed
in the end-user operating manual of final products.
Note 3: The module may be operated only with the antenna with which it is authorized. Any
antenna that is of the same type and of equal or less directional gain as an antenna that is
authorized with the intentional radiator may be marketed with, and used with, that intentional
radiator.