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KCX_BT_EMITTER Low cost bluetooth (BT) audio module


New Member
Very useful thread. I was not able to start. After going through thread I am able to interface receiver and play sound through emitter module.
But I want to configure it using serial port and have following issues if someone can guide

I am not getting response to any of AT commands
I am sending AT+ without any other character as suffix, this doesn't return me OK+
I am getting all device connected information, like MAC address, Name of Device on serial port.
I am using PC to interface emitter using docklite V2.2 software to interface.
connected through USB to serial converter CP2102 module.


New Member
Translation of Image :
Example and explanation of the AT command
Note: the name of the blue-tooth receiver used for the test is Bluetooth Audio, and the MAC address is 0x32a16c6f7f99.

<1>: Test Command
Send : AT+
Note: test communication is normal
Return value: OK+ (return response )

< 2>: system reset
Send : AT+REST
Description: reset
Return value: OK+ (return response )
REST (perform reset operation )
POWER ON (restart )

< 3>: query software version
Send : AT + GMR
Note: Check the software version
Return value: OK+ (return response )
К к к_ввееittertertertervv.x (return software version )

<4>: query connection status
Send : AT + STATUS
Description: search for Bluetooth connection status
Return value: OK+ (return response )
STATUS: x (x=0: no connection, x=1 connected )

< 5>: specify MAC address connection
Send : at + CONADD=0x32a16c6f7f99
Description: specify the MAC address link (here shows the device connected to the MAC-0x32a16c6f7f99 )
Return value: OK+ (return response )
CON: 32a16c6f7f99 (Bluetooth device connected to MAC=0x32a16c6f7f99 )
CONNECTED (successful connection )

<6>: disconnect
Send : AT + DISCON
Description: disconnect the current blue tooth
Return value: OK + DISCON (disconnect operation )
DISCONNECT (disconnected )

< 7>: Bluetooth device
Send : AT + SCAN
Description: search Bluetooth receive device, cycle search and list ? Blue tooth device information found
Return value: OK + SCAN (perform device search )
New Devices: 1 (Find the nth searched device )
MacAdd: 0x32a16c6f7f99 (this device's MAC address is 0x32a16c6f7f99)
Name: Bluetooth Audio (the Bluetooth name for this device is Bluetooth Audio)
ALL Devices=1 (the total number of devices currently searched is 1)

<8>: add automatically connected MAC address
Send : AT + ADDLINKADD=0x32a16c6f7f99
Description: with this command-set, a total of 10 MAC address records can be attached to 10 devices in a sequence.
Set the memory. When the module is started , it will search the MAC address of the device and the MAC address of the recording area.
The address is automatically connected to any one of the MAC addresses of the recording area, and is not connected when the address is not consistent, so as to achieve the specified MAC address connection.
When 10 recording spaces are empty , MAC address filtering is not performed ( by default, this area is empty in the factory).
Return value: OK+ (return response )
ADDLINKADD (execute MAC address memory )
VM_MacAdd 1 =0xb290cb8fa671 (MAC address Oxb290cb8fa671 memory success in VM Zone 1 storage area )
Note: a total of 10 MAC addresses can be stored, according to the storage in the MacAdd 1-MacAdd a total of 10, more than the maximum memory area will addr Mere
- no, no, no, no, no.

< 9>: add the Bluetooth device name for the auto connect
Send : AT + ADDLINKNAME=Bluetooth Audio
Note: with this command setting, specifying the blue tooth name connection, a total of 10 blue tooth names can be added, and 10 devices can be recorded sequentially on the chip.
Memory. When the module is started, it will search the blue tooth name of the device and the blue tooth name of the recording area.
The blue tooth name is automatically associated with any of the blue tooth names in the recording area , and is not associated with any of the blue tooth names in the recording area , so as to achieve the specified blue tooth name connection function . When 10
When all the recording spaces are empty , the blue tooth name is not filtered ( by default, this area is empty in the factory).
Return value: OK+ (return response )
ADDLINKNAME (execute MAC address memory )
VM_Name 1 =Bluetooth Audio (blue tooth name Bluetooth Audio) memory success in VM Zone 1 storage zone )
Note: a total of 10 blue tooth names can be stored, according to the storage in VM_Name1-VM_Name a total of 10, more than the maximum memory area will be an error Nate
More than 10!

<10>: query the auto-connect recording area
Send : AT + VMLINK?
Note: sending this command returns all information recorded in the automatically reconnected MAC and device name zones .
Return value :
ОК+VMLINK( 返 返 回 答 о )
В В_ADD_NUM-1 (Memory number of MAC addresses 0-9 a total of 10 )
В В_NAME_NUM=1 (memory device name address 0-9 total 10 )
Last_Add=0x32a16c6f7f99 (last time even hit the MAC address )
VM_MacAdd0=0xb290cb8fa671 (automatic reconnection Zone 1 MAC address )
VM_Name0=Bluetooth Audio (device name for auto reconnect Zone 1 )

<11>: delete all records in the auto-connect zone
Description: Remove all records from the auto reconnect zone (i.e., return to the state where the MAC address and device name are not filtered by default). )
Return value: Delete_Vmlink (perform the Delete operation )

May be this could further help others.
You have made it so simple for all of us


New Member
Can someone help in guiding as how to limit this module to get connected only to one desired receiver blue tooth module. I tried to store the Name as well as MAC address of one receiver in emitter memory. But if other receiver is on at that time it gets connected to that one first. And then it don't connect to the receiver whose MAC address is stored in emitter memory.


New Member
I just received two of those modules in V1.2 instead of V1.1. I cannot get those to work with either a Taotronics reciever or my Aftershokz trek tinanium headset. I tried the "easy connection" and "USB soundcard". I seems to start the pairing process, however no sound is ever sent, neither from line in nor USB input.
After the semi-pairing, it is listed on my computer as a sound output, but doesn't work.

I would have tried to debug this usinf the TX/RX pins but I don't own a serial port adapter.
Has any of you found anything that could explain my problems when spying the serial port ?



New Member
I also got some (5) of the modules stamped V1.2. When I queried them with AT+GMR they responded KCX_BTEMITTER_V1.1. I have had good luck using them, but have not tried the USB method; I am connecting them to a YX5200 via the "line in" inputs. I have a Github repository describing this plus Arduino code I use to program them here: https://github.com/Mark-MDO47/BluetoothAudioTransmitter_KCX_BT_EMITTER
The project I am using them for is a SciFi Rubber Band Gun; schematics and lots of info is here: https://github.com/Mark-MDO47/RubberBandGun
You can see the module transmitting to a Bluetooth speaker here:


Well-Known Member
Most Helpful Member
A very interesting and informative thread. Might have to get some of these.




New Member
Reply for spsrathore: I have not had the problem you described, connecting to the wrong bluetooth device even when the KCX_BTEMITTER is programmed to respond to something different. Is it possible that there is more than one device programmed in the KCX_BTEMITTER? The "VMLINK" memory can hold more than one device at a time.
In my experience (https://github.com/Mark-MDO47/Bluet...rammingArduino_SerialMonitor_SampleOutput.pdf), I had programmed the VMLINK to respond to a bogus address and then did a scan. It found my Bluetooth speaker but did not connect to it. It will auto-connect to the Bluetooth speaker if there is nothing in the VMLINK, or if the VMLINK is specifically programmed for my speaker. Maybe there is some other difference between your setup and mine that I am not aware of?


New Member
Fantastic stuff!! I've had one of these boards in a box for about 6 months with a "getting around to it" label on it. Your thread has given me the necessary information and impetus to try it out. Thanks for your efforts.


New Member
I realise faaxi has already done a full translation of the image, and many thanks for that. I quite often hit pages or images that need translation. Chrome does a pretty good job for the standard web pages. However it is possible to get the images translated as well. A webite called https://translate.yandex.com provides the ability to translate images. Which comes in handy, at least for me, for the situation here, or indeed when using a screen shot of a piece of software. I have included its efforts to translate the original image. Because of the mix of languages in the original image ( English and Chinese) I had to set the languages to Chinese -> English , rather than relying on the automatic selection. However as can be seen the results are more than acceptable.

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New Member
This is a fantastic thread, and I have been able to connect my KCX_BT_Emitter V1.2 PCBs (showing v1.1 via AT command) to an Anker SoundCore 2 speaker.
My main goal is to get the Apple AirPods Pro to work with the device.. has anybody made progress in this regard?

When I do AT+CONADD it seems to *kind of* connect, since issuing AT+DISCON afterwards makes the AirPods play the "disconnected" sound. However, there is no "connected" jingle, and no audio ever comes through in between the two commands.

Related question: Are there any other AT commands to raise/lower volume? Since the AirPods have no volume control, this would need to happen on the transmitter side...

Thanks everybody for the insightful posts so far!
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New Member
Hi guys, I am new for board add work. I need to add bluetooth transmitter board using "KCX_BT_EMITTER 5V" in tv. But I don't know what to do. Kindly any one provide video tutorials. And if and other boad available for the bluetooth audio transmitter kindly suggest...


Well-Known Member
Most Helpful Member
Apple doesn't play nice with any other device. I avoid Apple for that reason.


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