FSC-BT909C programming user guide

Introduction

Description

This design guide is suitable for engineers to develop FSC-BT909C series Bluetooth modules, also suitable for BT909 series modules

Module Default Settings

Name	FSC-BT909C-XXXX
LE-Name	FSC-BT909C-LE-XXXX
Pin Code	0000
Secure Simple Pairing Mode	ON
UART Baudrate	115200/8/N/1

Hardware Description

Pin Diagram

FSC-BT909C as an example:

Pin Description

Pin	Pin Name	Type	Pin Descriptions
1	UART_TX	O	UART TX
2	UART_RX	I	UART RX
3	UART_CTS	I/O	UART CTS
4	UART_RTS	I/O	UART RTS
11	RESET	I	External reset input: active Low
12	VDD	VDD	Power supply for I/O ports, DC 3.3V
13	GND	GND	GND
32	LED	I/O	Output square wave in pairing mode, output high level when bluetooth is connected
18	STATUS	I/O	bluetooth is not connected to output low level, connected to output high level
51	EXT_ANT	ANT	Change the 0 ohm resistance near the antenna, you can connect an external Bluetooth antenna

Hardware Design Notes

The simple test of the module only needs to connect VDD/GND/UART_RX/UART_TX to use
After drawing the schematic diagram, please send it to Feasycom for review,so as to avoid the Bluetooth distance not reaching the best effect

Function Description

Profiles & Features

SPP (Serial Port Profile)
GATTS (Generic Attribute Profile LE-Peripheral role)
GATTC (Generic Attribute Profile LE-Central role)
HFP-HF (Hands-Free Profile)
HFP-AG (Hands-Free-AG Profile)
A2DP-Sink (Advanced Audio Distribution Profile)
A2DP-Source (Advanced Audio Distribution Profile)
AVRCP-Controller (Audio/Video remote controller Profile)
AVRCP-Target (Audio/Video remote controller Profile)
HID-DEVICE (Human Interface Profile)
PBAP (Phonebook Access Profile)

GATT Default service and characteristic

Type	UUID	Characteristic	Description
Service	0xFFF0		throughput services
Write	0xFFF2	Write，Write Without Response	app send to module
Notify	0xFFF1	Notify	module send to app

Command Description

Terms

Throughout this specification:
Content between { } is optional
Content behind << represents a COMMAND from Host
Content behind >> represents a RESPONSE/EVENT to Host

Command Format

AT+Command{=Param1{,Param2{,Param3…}}}<CR><LF>

All commands start with “AT”, end with <CR><LF>
<CR> means “carriage return”, corresponds to hex value 0x0D
<LF> means “line feed”, corresponds to hex value 0x0A
If Command has Parameter, Parameter follows behind ‘=’
If Command has multiple Parameters, Parameter must be separated by ‘,’
If Command has Response, Response starts with <CR><LF>, ends with <CR><LF>
Module will always report command’s execution result by using “OK” for success or “ERR<code>” for failure

Error Code	Meaning
001	Failed
002	Invalid parameter
003	Invalid state
004	Command mismatch
005	Busy
006	Command not supported
007	Profile not turned on
008	No memory
Others	Reserved for future use

Example:Read module’s BR/EDR local name
<< AT+VER
>> +VER=FSC-BT1036-XXXX
>> OK

Event Format

<CR><LF>+Indication{=Param1{,Param2{,Param3…}}}<CR><LF>

All Events start with <CR><LF>, end with <CR><LF>
If Event has Parameter, Parameter follow behind ‘=’
If Event has multiple Parameters, Parameter must be separated by ‘,’
Use command AT+SEP to replace default separator for conflict prevention

Example: Received “1234567890” from mobile phone via SPP profile
>> +SPPDATA=10,1234567890

Commands Table

General Commands

AT+HELP - Firmware Function/Command Summary

Command	AT+HELP
Response	<FIRMWARE FUNCTION: appropriate working scenario > <OTA PATH: latest suitable firmware path on server for upgrade On-The-Air> <ENABLED PROFILES: LINKS: ON/OFF> … … <COMMAND SUMMARY: DESCRIPTION: PROFILE CATEGORY>
Description	Using help command to get the basic summary information

AT+SEP - Get/Set Event/Response Separator

Command	AT+SEP{=Param}
`Param`	hex value 0x01~0xFF, default: ‘,’ , specially, using ‘0’ instead of ‘xFF’ for convenience
Response	+SEP=Param
Description	The parameter of events/responses may contain value same to the default separator, using this command to replace default separator for conflict prevention (replace the default separator ‘,’ to hex value ‘xFF’ typically)

Example:Read module’s paired record (device name contains ‘,’ already)
<< AT+PLIST
>> +PLIST=1,32808,1C5CF226D773, Tony, iPhone12
>> +PLIST=2,40, A0BC30075421, Samsung S8
>> +PLIST=E
>> OK
Example: Replace separator to ‘0xFF’
<< AT+SEP=0
>> OK
Example: Read module’s paired record again
<< AT+PLIST
>> +PLIST=1<FF>32808<FF>1C5CF226D773<FF>Tony, iPhone12
>> +PLIST=2<FF>40<FF> A0BC30075421<FF>Samsung S8
>> +PLIST=E
>> OK

AT+VER - Get Firmware Version

Command	AT+VER
Response	+VER=Param1,Param2,Param3
`Param1`	Module type
`Param2`	Firmware version
`Param3`	Data of production
Note	The date of production in response will not be changed after firmware upgrade

Example:
<< AT+VER
>> +VER=BT1036,V2.6.1,20220922
>> OK

AT+BAUD - Get/Set Uart Baudrate

Command	AT+BAUD{=Param}
`Param`	2400/4800/9600/19200/38400/57600/115200(default)/128000/ 230400/256000/460800/512000/921600/1382400
Response	+BAUD=Param1,Param2,Param3
`Param`	All baudrates supported by current module
Description	Module will change baudrate to target value immediately or after reboot depending on firmware,BT1036、BT955、BT909C not support 2400

Example:Query baudrates supported by current module then change baudrate from 115200 bps to 921600 bps
<< AT+BAUD
>> +BAUD=2400,4800,9600,19200,38400,57600,115200,128000,230400,256000,
460800,512000,921600,1382400
>> OK

<< AT+BAUD=921600
>> OK
Module switch baudrate to 921600 immediately, host change baudrate as well, query module’s name at new baudrate
<< AT+NAME
>> +NAME=FSC-BT91036-1F26
>> OK

AT+REBOOT - Soft Reboot

Command	AT+REBOOT
Response	OK
Description	Module release all Bluetooth connections with remote device then reboot

Example:
<< AT+REBOOT
>> OK

AT+RESTORE - Restore Factory Settings

Command	AT+RESTORE
Response	OK
Description	Module restore all factory settings then reboot

Example:
<< AT+RESTORE
>> OK

AT+BTEN - Bluetooth On/Off

Command	AT+BTEN{=Param}
`Param`	0-Power off 1-Power on

AT+PROFILE - Bluetooth Profile Selection

Command	AT+PROFILE{=Param}
`Param`	A base-10 representation of a bit field, for each bit:
`BIT[0]`	SPP (Serial Port Profile)
`BIT[1]`	GATT Server (Generic Attribute Profile)
`BIT[2]`	GATT Client (Generic Attribute Profile)
`BIT[3]`	HFP-HF (Hands-Free Profile Handsfree)
`BIT[4]`	HFP-AG (Hands-Free Profile Audio Gateway)
`BIT[5]`	A2DP Sink (Advanced Audio Distribution Profile)
`BIT[6]`	A2DP Source (Advanced Audio Distribution Profile)
`BIT[7]`	AVRCP Controller (Audio/Video remote controller Profile)
`BIT[8]`	AVRCP Target (Audio/Video remote controller Profile)
`BIT[9]`	HID Keyboard (Human Interface Profile)
`BIT[10]`	PBAP Server (Phonebook Access Profile)
`BIT[15]`	iAP2 (For iOS devices)
Response	+PROFILE=Param
Description	GATT Server and Client, HFP Sink and Source, A2DP Sink and Source, AVRCP Controller and Target cannot be enabled simultaneously because of mutual exclusion.

Example:Read current profile selection
<< AT+PROFILE
>> +PROFILE=3
Example:Enable SPP profile, disable the others
<< AT+PROFILE=1
>> OK
Note: Only support spp、gatt、hid

AT+AUTOCONN - Power On Auto Reconnect Profile Selection

Command	AT+AUTOCONN{=Param}
`Param`	A base-10 representation of a bit field, format same with AT+PROFILE
Response	+AUTOCONN=Param
Description	Module will attempt to establish connection to devices in paired list after power on.

AT+STAT - Get All Profile State

Command	AT+STAT
Response	+STAT=Param1, Param2, Param3…
Description	Query all current enabled profile’s state

Example: Read current profile selection
<< AT+PROFILE
>> +PROFILE=83
Example:Read profile state
<< AT+STAT
+STAT=3,1,2,5
>> OK

AT+DEVSTAT - Read Device State

Command	AT+DEVSTAT
Response	+DEVSTAT=Param
`Param`	A base-10 representation of a bit field, for each bit:
`BIT[0]`	0: Power Off; 1: Power On
`BIT[1]`	0: BR/EDR Not Discoverable; 1: BR/EDR Discoverable
`BIT[2]`	0: BLE Not Advertising; 1: BLE Advertising
`BIT[3]`	0: BR/EDR Not Scanning; 1: BR/EDR Scanning
`BIT[4]`	0: BLE Not Scanning; 1: BLE Scanning

Example:usual combination and description

0	Device power off
1	Device power on
3	Device power on, BR/EDR Discoverable
5	Device power on, BR/EDR Not Discoverable, BLE Advertising
7	Device power on, BR/EDR Discoverable, BLE Advertising
13	Device power on, BR/EDR Not Discoverable, BLE Advertising, Scanning nearby BR/EDR devices

AT+ADDR - Get BR/EDR MAC Address

Command	AT+ADDR
Response	+ADDR=Param
`Param`	Module’s BR/EDR MAC address (12 Bytes ASCII)

Example:
<< AT+ADDR
>> +ADDR=DC0D30010203
>> OK

AT+LEADDR - Get BLE MAC Address

Command	AT+LEADDR
Response	+LEADDR=Param
`Param`	Module’s LE MAC address (12 Bytes ASCII)

AT+NAME - Get/Set BR/EDR Local Name

Command	AT+NAME{=Param1{,Param2}}
`Param1`	BR/EDR local name(1~31 Bytes ASCII)
`Param2`	MAC address suffix(0/1,default:1) 0: Disable suffix 1: Enable suffix “-XXXX” (lower 4 bytes of MAC address) after local name
Response	+NAME=Param
Description	Write local name if parameter exist, otherwise read current local name

Example:Read current BR/EDR local name
<< AT+NAME
>> +NAME=FSC-BT1036-XXXX
>> OK

Example:Change module’s BR/EDR local name to “ABC”,and disable suffix
<< AT+NAME=ABC,0
>> OK

Example:Change module’s BR/EDR local name to “ABC” and enable suffix
<< AT+NAME=ABC,1
>> OK

AT+LENAME - Get/Set BLE Local Name

Command	AT+LENAME{=Param1{,Param2}}
`Param1`	BLE local name(1~25 Bytes ASCII)
`Param2`	MAC address suffix(0/1,default:1) 0-Disable suffix 1-Enable suffix “-XXXX” (lower 4 bytes of MAC address) after local name
Response	+LENAME=Param

AT+SSP - Get/Set BR/EDR Pairing Mode

Command	AT+SSP{=Param}
`Param`	Pairing mode (0~3, default:2) (0) Legacy pairing, use pin code for pairing (1) Secure simple pairing, auto pairing (2) Secure simple pairing, display yes/no in pairing (3) Secure simple pairing, passkey compare, user need to accept/reject pair request with command AT+CFM
Response	+SSP=Param
Note	need reboot

AT+PIN - Get/Set BR/EDR Pin Code

Command	AT+PIN{=Param}
`Param`	Pin code(4~15 Bytes ASCII, default:0000)
Response	+PIN=Param
Description	Pin code only work in legacy pairing mode, see AT+SSP

Example:Read module’s pin code
<< AT+PIN
>> +PIN=0000
>> OK

Example: Change module’s pin code to “1234”
<< AT+PIN=1234
>> OK

AT+CFM - Accept/Reject Remote Pairing Request

Command	AT+CFM=Param1, Param2
`Param1`	12 Bytes MAC address of remote device
`Param2`	0-Reject remote pairing request 1-Accept remote pairing request
Description	Only used for pairing request in pairing mode 3, see AT+SSP

AT+COD: Get/Set Device Class

Command	AT+COD=Param
`Param`	Class of device(6 bytes ASCII, default:240408 Handsfree device)
Response	+COD=Param

Related configuration reference: COD.

AT+PAIR: Get/Set BR/EDR/BLE Visibility

Command	AT+PAIR=Param
`Param`	Mode(0-3) 0: Leave BR/EDR/BLE discoverable mode (stop advertising/broadcasting) 1: Enter BR/EDR discoverable mode (start broadcasting) 2: Enter BLE discoverable mode (start advertising) 3: Enter BR/EDR/BLE discoverable mode (start advertising/broadcasting)
Description	Module will always be discoverable if no device connected (BR/EDR or BLE), and be undiscoverable if connected with remote device, unless received this command

AT+PAGE: Get/Set BR/EDR Connectability

Command	AT+PAGE=Param
`Param`	Mode(0-1) 0: Leave BR/EDR connectable mode (stop paging) 1: Enter BR/EDR connectable mode (start paging)
Description	Module will always be connectable mode if no device connected, and be unconnectable if connected with remote device, unless received this command

AT+SCAN - Scan Nearby Devices

Command	AT+SCAN=Param1{,Param2{,Param3}}
`Param1`	scan type(0~3) 0: Stop scan 1: Scan nearby BR/EDR devices 2: Scan nearby BLE devices 3: Scan nearby BR/EDR/BLE devices
`Param2`	(1~48)Scan period. unit:1.28s, default:12.8s
`Param3`	(1~25 Bytes ASCII)Name filter. Filter scan results with name if set
Description	Format description reference: +SCAN - Scan Result

AT+PLIST - Get/Delete Paired List

Command	AT+PLIST{=Param}
`Param`	(0/1~8/12 Bytes MAC address) (0) Clear all paired record (1~8) Clear specific paired record with index (MAC) Clear specific paired record with MAC address
Response1	+PLIST=Param1, Param2, Param3{,Param4}
`Param1`	(1~8) Paired device’s index
`Param2`	A base-10 representation of a bit field, support profiles of device, see AT+PROFILE
`Param3`	(MAC) Paired device’s MAC address
`Param4`	(UTF8) Paired device’s name
Response2	+PLIST=E End of the paired record

Example:Read module’s paired record
<< AT+PLIST
>> +PLIST=1,32808,1C5CF226D773, iPhone12
+PLIST=2,40, A0BC30075421, Samsung S8
+PLIST=E
>> OK

Example:Clear module’s paired record
<< AT+PLIST=0
>> OK

AT+DSCA - Release All Connections

Command	AT+DSCA
Description	Module release all Bluetooth connections with remote device

AT+TPMODE - Turn On/Off Throughput Mode

Command	AT+TPMODE{=Param}
`Param`	Throughput mode(0~1，default:0） 0: Turn Off 1: Turn On
Response	+TPMODE=Param
Description	When SPP/GATT profile connected and throughput mode is on, the AT command will be de-active, every byte received via physical UART will be sent to air, vice visa

AT+SECCFG: Get/Set Security Level

Command	AT+PAIR=Param
`Param`	Mode(0-1),default:0 0: Level 0 1: Level 2

SPP Commands

AT+SPPSTAT - Read SPP State

Command	AT+SPPSTAT
Response	+SPPATAT=Param
Description	Format description reference: +SPPSTAT - SPP State

AT+SPPCONN - Establish SPP Connection

Command	AT+SPPCONN{=Param}
`Param`	MAC address of target device (12 Bytes ASCII)

AT+SPPDISC - Release SPP Connection

Command	AT+SPPDISC
Description	Release current SPP connection with remote device

AT+SPPSEND - Send Data Via SPP

Command	AT+SPPSEND=Param1,Param2
`Param1`	Payload length (1~492)
`Param2`	Payload (1~492 Bytes UTF8)
Description	If throughput mode is on, this command is de-active

Example: Send data “1234567890” to remote device via SPP
<< AT+SPPSEND=10,1234567890
>> OK

GATT Commands

AT+GATTSTAT - Read GATT State

Command	AT+GATTSTAT
Response	+GATTATAT=Param
Description	Format description reference: +GATTSTAT - GATT State

AT+GATTDISC - Release GATT Connection

Command	AT+GATTDISC
Description	Release current GATT connection with remote device

AT+GATTSEND - Send Data Via GATT

Command	AT+GATTSEND=Param1,Param2
`Param1`	Payload length (1~492)
`Param2`	Payload (1~492 Bytes UTF8)
Description	If throughput mode is on, this command is de-active

Example: Send data “1234567890” to remote device via GATT
<< AT+SPPSEND=10,1234567890
>> OK

HID Commands

AT+HIDSTAT - Read HID State

Command	AT+HIDSTAT
Response	+HIDATAT=Param
Description	Format description reference: +HIDSTAT - HID State

AT+HIDCONN - Establish HID Connection

Command	AT+HIDCONN{=Param}
`Param`	MAC address of target device (12 Bytes ASCII)

AT+HIDDISC - Release HID Connection

Command	AT+HIDDISC
Description	Release current HID connection with remote device

AT+HIDMODE - Get/Set HID Input Mode

Command	AT+HIDMODE{=Param}
`Param`	HID keyboard input mode (0~1), default 1 (0) Hex key code (1) Ascii key code (English)
Note	Module can support various keyboard language with specify firmware, such as:TURKEY SPAIN PORTUGAL FRANCE GERMANY ITALY CZECH JAPAN

AT+HIDDLY - Get/Set HID Report Period

Command	AT+HIDDLY{=Param}
`Param`	HID report period in millisecond, default 10 ms

AT+HIDSEND - Send HID Keyboard Report

Command	AT+HIDSEND=Param1,Param2
`Param1`	Report length
`Param2`	Report payload
Note	For special key code: 0x0D -> ENTER 0x08 -> BACKSPACE 0x09 -> TAB 0x20 -> SPACE

Example: Send key code ‘A’ to remote device (on AT+HIDMODE=1)
>> AT+HIDSEND=1,A
<< OK
Example: Send key code ‘A’ to remote device (on AT+HIDMODE=0)
<< AT+HIDSEND=2, x00 x04
>> OK
Note: As payload is hex value, hence actual command is:
41 54 2B 48 49 44 53 45 4E 44 3D 32 2C 00 04 0d 0a
Where:
00 : modifier
04 : key code
Module will auto send debounce key code by itself

AT+HIDCMD - Send HID User Report

Command	AT+HIDCMD=Param
`Param`	2 bytes hid user report e.g., for iPhone: Play/Pause: 00 CD Stop: 00 B7 Forward: 00 B5 Backward: 00 B6 Fast Forward: 00 B3 Rewind:00 B4 Record:00 B2 VolumpUp:00 E9 VolumpDn:00 EA Mute:00 E2 On screen keyboard Toggle:01 AE

Example: Send Volume Up to iPhone
<< AT+HIDCMD= x00 xE9
>> OK
Note: As the payload is hex value, hence actual command is:
41 54 2B 48 49 44 43 4D 44 3D 00 E9 0D 0A

Events Table

General Events

+PWRSTAT - Powering State

Format	+PWRSTAT=Param
`Param`	0-Powering off 1-Powering on(booting)
Description	AT Command is not recommended to be used while powering on/off state

+SCAN - Scan Result

Format1	+SCAN =Param1,Param2,Param3, Param4,Param5,Param6
`Param1`	Index
`Param2`	RSSI (-127 ~ -1)
`Param3`	Device address type (0~3) (0) BR/EDR address (1) LE public address (2) LE random address (3) iOS device with Carplay support
`Param4`	MAC address (12 Bytes ASCII)
`Param5`	Device Name for BR/EDR devices or advertising data for LE devices
`Param6`	Class of device(6 Bytes ASCII)
Format2	+SCAN=E: Scan stopped

Example: Scan BR/EDR nearby devices
<< AT+SCAN=1
>> OK
>> +SCAN=1,-32,3,B019C66209FA,wt-iphone,7A020C
>> +SCAN=2,-74,0,DC0D30000053,BW226,040680
>> +SCAN=3,-43,0,00158354F994,LAPTOP-3L,120104
>> +SCAN=E

+PAIRREQ - Pair Request

Format	+PAIRREQ=Param1,Param2{,Param3}
`Param1`	Passkey (000000~999999)
`Param2`	MAC address (12 Bytes ASCII) of current pairing device
`Param3`	Name of current pairing device

+PAIRED - Pair Result

Format	+PAIRED=Param1,Param2
`Param1`	Pair result (0)-Success (1~255)-Failed reason
`Param2`	MAC address (12 Bytes ASCII) of current pairing device

SPP Events

Note

Events for iAP2 (Apple Accessory Protocol) and AAP (Android Auto Protocol) are almost the same with SPP, which are:

+IAPSTAT, +IAPDATA for iAP2 profile
+AAPSTAT, +AAPDATA for AAP profile

Document will omit these events.

+SPPSTAT - SPP State

Format	+SPPSTAT=Param
`Param`	(0) Unsupported (1) Standby (2) Connecting (3) Connected

+SPPDATA - SPP Received Incoming Data

Format	+SPPDATA=Param1,Param2
`Param1`	Payload length
`Param2`	Payload

Example: Received data “1234567890” from remote device via SPP

<< +SPPDATA=10,1234567890

GATT Events

+GATTSTAT - GATT State

Format	+GATTSTAT=Param
`Param`	(0) Unsupported (1) Standby (2) Connecting (3) Connected

+GATTDATA - GATT Received Incoming Data

Format	+SPPDATA=Param1,Param2
`Param1`	Payload length
`Param2`	Payload

Example: Received data “1234567890” from remote device via GATT

<< +GATTDATA=10,1234567890

HID Events

+HIDSTAT - HID State

Format	+HIDSTAT=Param
`Param`	(0) Unsupported (1) Standby (2) Connecting (3) Connected

Application scenarios

Read/Write Parameters

MCU change device name CARKIT reference code:

void change_name(void)
{
    uart_send("AT+NAME\r\n");
    if(uart_read("+NAME",name_buf))
    {
        if(memcmp(name_buf,"CARKIT",6))
        {
            uart_send("AT+NAME=CARKIT,0\r\n");      //defalut disable MAC address suffix
            uart_send("AT+NAME\r\n"); // read bt name
            if(uart_read("+NAME",name_buf))
            {
                if(memcmp(name_buf,"CARKIT",6))
                {
                    //change name fail
                }
                else
                {
                    //change name success
                }
            }
        }
    }
}

Note

modify any parameters, it is recommended to query first and then modify the final verification

Data Throughput

Typical SPP Slave Data Throughput Interaction:

SPP Master-Slave

One of the standard firmwares of the module simultaneously supports SPP master and SPP slave features, when the user use the AT commands for the SPP master feature, the module will act as master role, otherwise, it acts as slave role.
The list of AT commands for the SPP master feature:

Commands	Description
AT+SCAN	Scan nearby devices
AT+SPPCONN	Establish SPP connection
AT+SPPSTAT	Read SPP state
AT+SPPDISC	Release SPP connection
AT+SPPSEND	Send data via SPP

Typical AT-Command Mode SPP Master Interaction:

Appendix

Download PDF Document

Download PDF Document