Wireless Bluetooth Audio Transmitter Module

Wireless Bluetooth Audio Transmitter Module

1. Description:
It is a Wireless Bluetooth Audio Transmitter Module. The module is a Bluetooth audio
transmitter module integrating computer USB sound card to Bluetooth transmission and
line audio input and transmission. It adopts Bluetooth 5.1 technology to greatly ensure the
quality and stability of audio transmission. This product can be used in most desktop
computers, laptops, televisions, projectors, game consoles, iPad, CD players, MP3 and
other products without Bluetooth transmission function, Send audio signals to Bluetooth
audio receiving devices such as Bluetooth headset or Bluetooth speaker to form a wireless
audio transmission system, so that your life can truly enter the wireless era!
2. Features:
1>.Stereo audio input
2>.SMD ultra small size
3>.Simple and easy to
use 4>.LED work state
indicator
5>.UART programmable control
6>.Integrated transceiver
3. Parameters:
1>.Product name:Wireless Bluetooth Audio Transmitter Module
2>.Model:KCX_BT_EMITTER
3>.Work Voltage:DC 3.3V-5V
4>.Work Current:30mA-45mA
5>.Work
Frequency:2402~2485MHz
6>.Transmit power:
+5dBm(MAX) 7>.Dynamic
Range:80dB 8>.THD+N:-70dB
9>.Audio Frequency
Response:20Hz~20KHz 10>.SNR:95dB
11>.Input/Output Signal
Amplitude:<2Vpp 12>.Track:Dual
channel(Stereo) 13>.Transmission
Delay:250-300mS 14>.Work
Temperature:-20℃~85℃ 15>.Work
Humidity:0%~95%RH 16>.Module
Size:23.5*15.5mm
4. Work Mode:
1>.Set Work Mode:
1.1>.There are two pads marked ‘TX/RX’ which are used to working in Bluetooth
Transmitter Mode or Bluetooth Receiver Mode.
1.2>.Bluetooth Transmitter Mode: Two pads disconnected as default.
Indicator is red. 1.3>.Bluetooth Receiver Mode: Two pads connected.
Indicator is blue.
2>.Bluetooth Transmitter Mode:
2.1>.It can send input audio from U-disk/Line audio/sound cards to other Bluetooth
receivers through Bluetooth, such as Bluetooth headphones, Bluetooth speakers, etc.
2.2>.Bluetooth not connected: Red indicator fast flashing at a constant
speed. 2.3>.Bluetooth connection successful: Red indicator fast flashing twice
every 5 seconds.
2.4>.Line Audio Input. Audio signal input from phone, MP3, CD, TV and so on via IN_L
and IN_R audio input terminal.
2.5>.USB Sound Card Function. It can get audio signal from PC USB interface via DP
and DM audio input terminal.User needs to set the device as the default player in the

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 Wireless Bluetooth Audio Transmitter Module

audio manager of the computer after connecting the computer.

3>.Bluetooth Receiver Mode:
3.1>.It can send input audio from smartphones/tablets to
loudspeaker/amplifier. 3.2>.Bluetooth not connected: Blue indicator fast
flashing at a constant speed. 3.3>.Bluetooth connection successful: Blue
indicator fast flashing twice every 5 seconds.
4>.Simple Connection Method:

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4.1 >.It will automatically search and connect to your Bluetooth receiver after
power ON. It will store the MAC address of the receiver after the connection is successful.
4.2 >.Automatically connect to the last Bluetooth receiver for next power ON.
4.3 >.Replace the paired receiver. Press button to disconnect current Bluetooth
device and pair the new device again.
4.4 >.The automatic search time is about 10~15 second.
4.5 >.Note: it cannot be connected to the receiver which need input pair
password by default.
5>.Custom connection method:
5.1 >.It needs connect via AT control commands.
6>.Button Function:
6.1 >.Short Press: Disconnect current Bluetooth device and pair the new device.
6.2 >.Keep Press 2 second: Switch audio input source from LINE terminal or USB
terminal. Note:It is available when connecting U-disk.
5. Pin Definition:
1>. +5V : Input voltage positive pole.
2>.PGND : Input voltage negative pole.
3>.LINK : Work status output indicator. Output 3.3V when connected,otherwise
output 0V. 4>.RX : UART receive terminal.
5>.TX : UART send terminal.
6>.AUDIO_L : Left channel audio input/output.
7>.AUDIO_R : Right channel audio input/output.
8>.AGND : Audio GND input.
9>.DP : USB Communication terminal.
10>.DM : USB Communication
terminal.
11>.CONNECT: Trigger signal input terminal.Low level available. Its function is the same
to button.
6. AT Control Command:
1>.Test
Send: AT+
Return:
OK+
Explain: Check whether the communication is normal.
2>.Reset
Send: AT+REST
Return: OK+REST (//Executing command
operation) POWER ON (//Restart the
power supply)
3>.Get Current UART Baud Rate
Send: AT+BAUD?
Return: OK+BAUD= n , BAUD=baud (//Return current UART
baud rate) Note: baud’s range is 0-4 as following:
n=0, 9600
n=1, 19200
n=2, 38400
n=3, 57600
n=4, 115200
4>.Set Current UART Baud Rate
Send: AT+BAUD=n
Return: OK+BAUD= n , BAUD=baud (//Return current UART
baud rate) Note: baud’s range is 0-4 as following:
n=0, 9600
n=1, 19200
n=2, 38400
n=3, 57600
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 Wireless Bluetooth Audio Transmitter Module

n=4, 115200
Explain: The chip will restart after successful setup.
5>.Query Software Version
Send: AT+GMR?

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Return: OK+VERS: KCX_BT_RTX_V1.x

Explain: The version is constantly updated, and the actual return value will be
inconsistent with this.
6>.Query Current Work Mode
Send: AT+BT_MODE?
Return: OK+BT_EMITTER (//Currently working in transmitter
mode) OK+BT_RECEIVER (//Currently working
in receiver mode)
7>.Shutdown
Send: AT+POWER_OFF
Return: OK+POWEROFF_MODE (//Inter
shutdown) Note: It need press button or re-
power to power ON.
8>.Query Current Playing Audio Source
Send: AT+CHANNEL?
Return: OK+CHANNEL=BT CHANNEL (//Get audio from
Bluetooth) OK+CHANNEL=LINE CHANNEL (//Get audio
from LINE terminal) OK+CHANNEL=PC CHANNEL (//Get
audio from USB terminal)
9>.Set Current Playing Audio Source
Send: AT+CHANNEL=ch
Return: ch=0 (//Reserved,
unavailable) ch=1 (//LINE
audio input)
ch=2 (//USB audio input)
10>.Query Connection Status
Send: AT+STATUS?
Return: OK+STATUS:0 (//Bluetooth connection
successful) Return: OK+STATUS:1(//Bluetooth not
connected)
11>.Get Bluetooth Name
Send: AT+NAME?
Return: OK+NAME=XXXX (//XXXX is current Bluetooth
name) Note: This command is available in receiver mode.
12>.Set Bluetooth Name
Send: AT+NAME+name
Return: OK+NAME=XXXX (//XXXX is current Bluetooth
name) Note: This command is available in receiver mode.
Explain: The chip will restart after successful setup.
13>.Get Bluetooth MAC address
Send: AT+MAC?
Return: OK+MAC: (mac) 3f3734a1c450 (//mac is
6byte) Note: This command is available in receiver
mode.
Explain: 3f3734a1c450 is a MAC address from tested Bluetooth device. Different
devices have different MAC addresses.
14>.Get Volume
Send: AT+VOL?
Return: OK+VOL=XXX (//XXX is current volume value)
Note: XXX’s range is 00~31 and the default value is 31 in the maximum volume.
15>.Set Volume
Send: AT+VOL=XXX
Return: OK+VOL=XXX (//XXX is current volume value)
Note: XXX’s range is 00~31 and the default value is 31 in the maximum volume.
16>.Play/Pause
Send: AT+PAUSE
Return: OK+PAUSE
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(//Pause) OK+PLAY
(//Play)
17>.Get Play/Pause Status
Send: AT+PAUSE?
Return: OK+PAUSE (//Pause
status) OK+PLAY
(//Play status)
18>. Disconnect current Bluetooth and pair the new device

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Send: AT+PAIR
Return: OK+PAIR (//Pause
status) Note:Its function is the
same to button.
19>.Search for Bluetooth devices
Send: AT+SCAN
Return: OK+SCAN (//Perform a device search operation)
New Devices:N (//Nth device found, N can be 1 or 2 or 3 and so on)
MacDdd:0x32a16c6f7f99 (//MAC address of the device is 0x32a16c6f7f99)
Name:Bluetooth Audio (//Bluetooth name is Bluetooth Audio)
ALL Devices:N (//Total number of all devices currently searched)
Explain: 0x32a16c6f7f99 is a MAC address from tested Bluetooth device. Different
devices have different MAC addresses.
20>.Add MAC address for automatic connection
Send: AT+ADDLINKADD=0x32a16c6f7f99
Return: OK+ADDLINKADD=0x32a16c6f7f99 (//Perform
operation) BT_ADD_NUM=add_num (//add_num’s range is
00-09) BT_NAME_NUM=name_num (//Perform operation)
Audio_link_Add:Audio_link mac (//Perform operation)
VM_MacAdd add_num=0x32a16c6f7f99 (//MAC address added successfully
in the VM area's vm_ Num storage area)
Explain: 0x32a16c6f7f99 is an example MAC address. User needs to enter the MAC
address of the actual receiver.
Explain: This command is used to set the connection to the specified Bluetooth device
to avoid being forcibly connected by other devices.
Note: It can add up to 10 MAC addresses, so the value of add_num is 00~09. More
than 10 will return an error prompt: Addr More than 10.
Note: This command is available in transmitter mode.
21>.Add Bluetooth name for automatic connection
Send: AT+ADDLINKNAME=Bluetooth Audio (//Bluetooth name is Bluetooth
Audio) Return: OK+ADDLINKNAME (//Perform operation)
VM_NAME N=Bluetooth Audio (//Bluetooth name added successfully)
Explain: Bluetooth Audio is an example Bluetooth name. User needs to enter the
Bluetooth name of the actual receiver.
Note: It can add up to 10 Bluetooth name, so the value of N is 00 ~ 09. More than 10
will return an error prompt: Name More than 10
22>.Query automatic connection record information
Send: AT+VMLINK?
Return: OK+VMLINK
BT_ADD_NUM=N (//Number of MAC recorded)
BT_NAME_NUM=N (//Number of Bluetooth name
recorded) Last_Add=0x32a16c6f7f99 (//The last
connected MAC address)
VM_MacAdd0=0xb290cb8fa671 (//MAC address for automatic reconnected)
VM_NAME0=Bluetooth Audio (//Bluetooth name for automatic reconnected)
23>.Delete automatic connection record information
Send: AT+DELVMLINK
Return: Delete_Vmlink
7. Application:
1>.DIY Bluetooth transmitter
equipment 2>.Audio device converter
3>.Add wireless function to the device
8. Package:
1>.1pcs Wireless Bluetooth Audio Transmitter Module

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Wireless Bluetooth Audio Transmitter Module