RF-Star EFR32BG22 User manual

EFR32BG22 Bluetooth Low Energy 5.0
Master-Slave Module and Protocol
Version: V1.7
Shenzhen RF-star Technology Co., Ltd.
Jun. 8th, 2022

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Revision History
Date
Version No.
Description
2020.09.28
V1.0
The initial version is released.
2021.01.16
V1.1
Add device information Service.
Add RF-BM-BG22Ax series module description.
Add Bluetooth pairing function.
Add AT command to configure the serial port packet size and delay time.
Update the stable transmission rate.
Add the serial port hardware flow control, and adjust RTS and CTS pins into PB1
and PB2 respectively (previously PC2 and PC3).
Add the function of scanning broadcast response packets in observer mode.
Add Long Range broadcast.
Add the command to enter the authentication key for the master role.
Add sleep command.
Add the PHY setting commands for the master role when scanning and connecting.
Modify most commands from taking effective after reboot to taking effect
immediately.
Modify the minimum TX power from -30 dBm to -28 dBm.
Update the MCU reference code.
Update the peripheral reference design.
Update the measured power consumption.
2021.01.21
V1.2
Update the serial port pins.
Update the stable transmission rate.
Update the measured power consumption.
2021.03.10
V1.3
Adjust the setting method of the broadcast name, user-defined broadcast, and
extended broadcast.
Add a carriage return and line feed when APP sends AT command.

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Change the default connection PHY from 2M PHY to 1M PHY.
Modify the function that the handle value sent by the current master always points
to the newly established connection when a connection is established.
Cancel the master-slave identity setting command in the master-slave mode, and
the set transparent transmission handle determines whether the current data is
transparently transmitted to the master or the slave in the master-slave mode.
Add the collected battery voltage parameters and button detection parameters into
the broadcast package.
Add the enhanced broadcast function in Beacon mode.
Add the observer filtering function.
Add the function of scanning the expanded broadcast.
Add the function of setting the broadcast response packet data by AT command.
Add FCC and CE certificates.
2021.12.30
V1.4
Change the storage mode of the broadcast response packet to power-off save.
Optimize the AT+SCAN to scan the broadcast name type of Shortened Local Name
(08 type).
Update the chapter description.
2022.05.12
V1.5
Add the filter conditions of the broadcast data in Observer mode.
Add the serial port wake-up function in the Sleep command.
Add the function of reading the specified UUID.
Add the function of The automatic reconnection command increases the setting to
trigger the reconnection parameter immediately
Delete the duplicate function of "AT+DEV_DEL=?".
Add IPEX version module dimension and footprint.
Add the power consumption and the serial port power consumption data at 6 dBm.
Update the module power-on stabilization time to 600 ms.
Update the chapter description.
2022.06.08
V1.6
Update the chapter description.
Update the pin attribute diagram.
2022.08.02
V1.6
Add the RF-BM-BG22Bx and RF-BM-BG22Cx descriptions.

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Update the chapter description.
2022.08.10
V1.7
Add the max. voltage specification of the RESET pin.
Add the reference design of BG22Bx and BG22Cx modules.
Note:
1. The document will be optimized and updated from time to time. Before using this document, please make sure it is
the latest version.
2. To obtain the latest document, please download it from the official website: www.rfstariot.com, www.szrfstar.com.

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Table of Contents
Revision History .................................................................................................................................................................. 1
Table of Contents................................................................................................................................................................ 4
1 Overview ............................................................................................................................................................................ 8
1.1 Introduction........................................................................................................................................................... 8
1.2 Features ................................................................................................................................................................ 8
1.3 Working Mode Specification ........................................................................................................................10
1.4 Default Configurations in Slave Mode .....................................................................................................10
1.5 Default Configuration in Beacon Mode ...................................................................................................10
1.6 Description of Default Broadcast Data ....................................................................................................11
1.7 Device Status Specifications.......................................................................................................................11
1.8 Multi-Connection ..............................................................................................................................................12
2 Package and Pin Assignment ..................................................................................................................................14
2.1 RF-BM-Ax(I).......................................................................................................................................................14
2.2 RF-BM-Bx...........................................................................................................................................................19
2.3 RF-BM-Cx...........................................................................................................................................................22
3 UART Transparent Transmission Protocol (Bridge Mode) ...........................................................................25
4 BLE Protocol Specification (APP Interface) .......................................................................................................26
UART Service UUID...............................................................................................................................................26
BLE Data Receiving UUID (RX Characteristic) ...........................................................................................26
BLE Data Transmitting UUID (TX Characteristic).......................................................................................26
AT Command Operation UUID...........................................................................................................................26
Device Information UUID: 0x180A....................................................................................................................27
Manufacturer Name................................................................................................................................................27
Hardware Revision .................................................................................................................................................27
Firmware Revision ..................................................................................................................................................27
System ID...................................................................................................................................................................27
Generic Access UUID: 0x1800 ..........................................................................................................................28
Device Name.............................................................................................................................................................28
Device Appearance ................................................................................................................................................28

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Peripheral Preferred Connection Parameters..............................................................................................28
Central Address Resolution.................................................................................................................................28
5 AT Command..................................................................................................................................................................29
5.1 AT Command Format .....................................................................................................................................29
5.2 AT Command List.............................................................................................................................................30
5.3 Detailed AT Command...................................................................................................................................33
•Enter AT Command Mode ......................................................................................................................33
•Exit AT Command Mode .........................................................................................................................33
•Device Name...............................................................................................................................................33
•MAC Address ..............................................................................................................................................34
•Device Role..................................................................................................................................................34
•TX Power ......................................................................................................................................................35
•Broadcast Parameter ...............................................................................................................................36
•User-defined Broadcast Data................................................................................................................37
•User-defined Broadcast Response Packet Data...........................................................................37
•Long Range Broadcast............................................................................................................................38
•Extended Broadcast (Big Broadcast Packet)..................................................................................39
•Beacon...........................................................................................................................................................40
•Scan as a Master.......................................................................................................................................41
•PHY of Master Role..................................................................................................................................42
•Scan and Print Out Slave Device Name...........................................................................................43
•Connection as a Master ..........................................................................................................................44
•Display the Connected Devices ...........................................................................................................45
•Disconnection..............................................................................................................................................45
•Automatic Reconnection.........................................................................................................................46
•Delete Automatic Reconnection Device............................................................................................48
•Connection Interval...................................................................................................................................48
•Designate Transmission Device...........................................................................................................49
•Set the UUID of Slave Role ...................................................................................................................50
•Enable/Disable UUID Configuration Function of Master Role .................................................51
•Configure UUID of Master Role ...........................................................................................................52
•Master Role Reads the Specified UUID Data.................................................................................53
•Send Data by AT Command..................................................................................................................53

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•Observer........................................................................................................................................................54
•PHY Rate......................................................................................................................................................56
•Baud Rate.....................................................................................................................................................57
•Serial Port Frame Size and Timeout Time .......................................................................................58
•Serial Port Echo .........................................................................................................................................59
•Device Status Display..............................................................................................................................59
•User Authentication...................................................................................................................................60
•Enter User Authentication Key..............................................................................................................61
•Pairing Function of Slave Role .............................................................................................................61
•Pairing Function of Master Role...........................................................................................................62
•Enter Pairing Passkey of Master Role...............................................................................................64
•Pairing List....................................................................................................................................................64
•Delete Paired Device................................................................................................................................65
•Sleep Mode..................................................................................................................................................65
•Enable/Disable Watchdog......................................................................................................................67
•Restart Device ............................................................................................................................................67
•Reset Device ...............................................................................................................................................67
•Query Firmware Version .........................................................................................................................68
6 Transparent Transmission Test ...............................................................................................................................69
6.1 Test by APP (Android)....................................................................................................................................69
6.2 Test by PC End.................................................................................................................................................71
Preparation before Use................................................................................................................................71
Connection Steps...........................................................................................................................................72
7 iOS APP Programming Reference.........................................................................................................................77
8 MCU Reference Code (Transparent Transmission)........................................................................................79
9 Hardware Specifications ............................................................................................................................................80
9.1 Module Parameters.........................................................................................................................................80
9.2 Antenna................................................................................................................................................................80
9.2.1 Antenna Design Recommendation ..............................................................................................80
9.2.2 Antenna Output Mode Modification..............................................................................................81
9.2.3 External Antenna Design Recommendation of the Half-Hole ANT Pin..........................82
9.3 Reference Design............................................................................................................................................83
9.3.1 RF-BM-BG22Ax(I) ..............................................................................................................................83

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9.3.2 RF-BM-BG22Bx...................................................................................................................................84
9.3.3 RF-BM-BG22Cx ..................................................................................................................................84
9.4 Basic Operation of Hardware Design ......................................................................................................85
9.5 Trouble Shooting..............................................................................................................................................85
9.5.1 Unsatisfactory Transmission Distance........................................................................................85
9.5.2 Vulnerable Module..............................................................................................................................86
9.5.3 High Bit Error Rate .............................................................................................................................86
9.6 Electrostatics Discharge Warnings ...........................................................................................................86
9.7 Soldering and Reflow Condition.................................................................................................................86
10 Contact Us ....................................................................................................................................................................88
Appendix A:.........................................................................................................................................................................89
FCC ..............................................................................................................................................................................89
CE..................................................................................................................................................................................90
Appendix B: Power Consumption Test Screenshot ............................................................................................91
1 Sleep Mode: 3.23 μA..........................................................................................................................................91
2 Broadcast Mode...................................................................................................................................................91
2.1 0 dBm, 200 ms broadcast cycle: 57.82 μA...................................................................................91
2.2 0 dBm, 500 ms broadcast cycle: 24.13 μA...................................................................................92
2.3 0 dBm, 1000 ms broadcast cycle: 15.12 μA ................................................................................92
3 Connection Mode ................................................................................................................................................93
3.1 0 dBm, 30 ms connection interval: 146.74 μA.............................................................................93
3.2 0 dBm, 100 ms connection interval: 34.68 μA.............................................................................93

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1 Overview
1.1 Introduction
The Bluetooth LE modules which are mentioned in this document can work in bridge mode (transparent transmission
mode).
In bridge mode, user MCU can communicate with the mobile device bi-directionally through the universal serial ports
of modules. Users can also manage and control certain communication parameters through specific AT commands of
serial ports. The detailed meaning of the user data is defined by the upper applications. Mobile devices can operate the
write to the module through the APP. And the data written will be sent to the user MCU through serial ports. Then the
module will transmit the data packets from the user MCU to the mobile devices automatically. Under the development
in this mode, the user needs to undertake the code design for the MCU and the APP for mobile devices.
In order to ensure the stability of the program, the module will start to work normally after it is powered on for 600 ms.
When transmitting a big-size data packet, it is recommended to start working after the module is connected for 6 s. MTU,
connection interval, and other operations need to be confirmed when a connection is established, if the high-speed
transparent transmission is carried out at this time, packet loss or device jamming is very easy to occur.
1.2 Features
1. Easy to use, no need for any application experience of Bluetooth protocol stack.
2. Support all features of BLE 5.0: 2M PHY, Long Range broadcast, Extended broadcast. Modules based on
EFR32BG22C112 don’t support Long Range broadcast.
3. Support BLE master mode, slave mode, master-slave mode, and Beacon mode.
4. Support concurrent slave and master roles, that is, the module can connect to other slave devices when it is
connected by one master device (master-slave mode).
5. Support multi-connection during master mode and master-slave mode. Up to 8 slave devices can be connected
concurrently under master mode. Under master-slave mode, 7 slave devices can be connected concurrently, and
it also can be connected as a slave by another master device at the same time.
6. Default connection interval of 20 ms, which makes quick connections and enhances the compatible stability of
Android and iOS phones.
7. Universal serial port design for user interface, full-duplex bi-directional communication, and support the minimum
baud rate of 1200 bps and the maximum baud rate of 921600 bps.
8. Support software reset module by AT command.
9. Support acquire and modify the MAC address (take effect after resetting) by AT command.
10. Support modify the Bluetooth connection interval and control different transmit rates (dynamic power consumption

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adjustment) by AT command.
11. Support the modification of the transmit power, the broadcast interval, the serial port baud rate, and the module
name by AT commands, please check for details in AT Command.
12. Support modify the Service UUID by AT command.
13. Support modify serial port frame size and timeout time by AT command.
14. In the master or master-slave mode, support the user-defined selection of the UUID channel for receiving and
sending.
15. AT commands can be sent through APP or serial port.
16. High-speed transparent transmission rate, stable transmission at 50 KB/s (512000 bps).
17. Support to modify the PHY communication speed: 1M, 2M, LE Coded (125 kbps & 500 kbps).
18. Support user-defined broadcast data, the longest user-defined length is 26 bytes.
19. Support extended broadcast packets, a maximum of 251 bytes of an extended broadcast packet can be user-
defined.
20. Support setting Long Range broadcast packet (Long Range/LE Coded).
21. Support setting Bluetooth pairing and bonding functions.
22. Ultra-low working power consumption, the measured power consumption of the module is as follows (When the
watchdog function is turned off, the power consumption will be lower by 2 ~ 3 μA overall):
Table 1. Power Consumption
Event
Average Current
Test Condition / Remark
Sleep
3.02 µA
No Broadcast
Broadcast interval: 200 ms
57.82 μA
0 dBm
101.89 μA
6 dBm
Broadcast interval: 500 ms
24.13 μA
0 dBm
41.20 μA
6 dBm
Broadcast interval: 1000 ms
15.12 μA
0 dBm
24.78 μA
6 dBm
Connection interval: 20 ms
146.74 μA
0 dBm
181.01 μA
6 dBm
Connection interval: 1000 ms
9.39 μA
0 dBm
11.64 μA
6 dBm
Open serial port
1.2 mA
Turn off broadcasting