Bluetooth audio, someone?

[malium]

Hello,

I ordered wrong bluetooth stereo module by mistake... Now, its a master module, but I do not know how to read this diagrams for connection:

http://www.ebay.com/itm/NEW-XS3868-Bluetooth-Stereo-Audio-Module-OVC3860-Supports-A2DP-AVRCP-/331001175174?pt=LH_DefaultDomain_0&hash=item4d11351c86

http://www.ebay.com/itm/1-pcs-XS3868-Bluetooth-stereo-audio-module-witth-OVC3860-Supports-A2DP-AVRCP-A-/281141345871?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4175547e4f

I wanted this one:

http://www.ebay.com/itm/Bluetooth-stereo-audio-Transmitter-Receiver-module-headset-computer-speaker-B-/161052847791?pt=LH_DefaultDomain_0&hash=item257f7f6eaf

Which has connectors of my interest clearly stated, but I cannot figure out if this can be done with the one from above, which I got in the end.
I would like to use this module in portable speaker system, so I could stream music from cell phone for example. I suppose this module should be connected as amplifier imput, but I can't figure out which are connectors on the module, which should then be wired to input l/r at the amp.
Anybody can maybe help?

Thanks in advance...

[xpertvis]

Hi. I had one of those modules, but i burned it, after 10 minutes. Sadly is, that i don't know what hapened, because module was running for 10 minutes with no problem.
Anyway, i had same problem with connection. I wasn't able to find right DS with right pinout of module. So i tracked traces from chip.  If you are still looking for help, let me know.
BWT all modules you mentioned are same, only board layout is different,  and also that one with blue board have better documentation. And you need to use amplifier with all of them.

[MrAureliusR]

Looks to me like you have the correct module for receiving audio, so you could indeed make a wireless speaker system with it.

Have you tried powering it up, and searching for it with your cellphone/tablet/other bluetooth adapter (laptop/bluetooth card in a PC?)? That would be my first step. Then look at the datasheet for it, read about similar projects, figure out what each pin does and then wire it up...

Let me know if you need more help.

EDIT: Here's the datasheet, scroll down to page 6 (it's not all in Chinese) : http://www.icstation.com/ebay/PDF/XS3868M.pdf

Page 8 also has example circuits.

ANOTHER EDIT: The more I read, the more I realize what you mean. This does actually appear to be a transmitter. In that case you're screwed. Check out https://www.sparkfun.com/products/11678 maybe? They also have a breakout for that module, at https://www.sparkfun.com/products/11777 though for an additional $25 I'm not sure it's worth it unless you have zero experience with a soldering iron.

Here's an ever easier all in one solution: http://www.ebay.com/itm/BC05-B-Demo-Version-Bluetooth-Audio-Module-A2DP-HFP-Stereo-Audio-/130926126094?pt=LH_DefaultDomain_0&hash=item1e7bce240e

[xpertvis]

every module malium linked is BT receiver. Even if it has "transmiter" in description. They all have same chip OVC3860, which is BT receiver. No transmitting capable. BT receiver that malium bought is perfectly ok, but it is imposible to find right DS for it. Real pinout number of board is different from that in DS.

[MrAureliusR]

what do you mean by 'right DS'? The datasheet I found seems to be for that exact module?

[xpertvis]

modules i have are with 12 pins on one side, and 11 on other side. When you look in DS, there is different number of pins. One of module i have is 3 months old, other one i just received last week. They are same, so malium has probably same module as i have.

[xpertvis]

So as I said, i have BT module with OVC3860  chip on green pcb. I was looking for connection between OVC chip and pads on pcb, so based on this DS:http://www.szriley.com/DownLoadFile/OVC3860.pdf i can make right connection. Here is a picture of BT module with numbers: (Attachment: 1.png). These numbers are pins of OVC3860 connected to pads.

I compared these numbers with this schematic: http://www.electrodragon.com/w/images/6/60/PKB_schematic.jpg, which is schematic of BT module on blue pcb, this one: http://www.elecfreaks.com/wiki/images/thumb/9/9d/BLK-MD-SPK-B-B.jpg/500px-BLK-MD-SPK-B-B.jpg. This module has better documentation (well, not so much better, but in DS this module is with 26 pads, and in real life it is also with 26 pads. In contrast with "green" module, which in DS has 25 pads, but in real life has only 23. Take a look: http://www.icstation.com/ebay/PDF/XS3868M.pdf)
Then, based on this connection: http://www.electrodragon.com/w/images/0/03/BLK-MD-SPK-B_DEMO_MUTE.pdf i made this circuit:  (Attachment: 2.png). It is minimum circuit without charging option.

I used lipo battery charged to 4 volts, connected audio output to my stereo. First, I had high current consumption. In idle ~70mA, connected ~100mA, with playing music ~120mA. This was due some short connection somewhere around audio output area. Now, without that short i have ~40mA in idle, ~60mA in connected with phone, and ~78mA when music is playing. But it is still more than it should be (according to DS, it should be ~26mA in idle).

Also i had problem with high frequency noise, like from antena or something (dont know). Noise was heard all the time, but it was even worse when BT module was waiting for connection. Based on this article: http://www.penguin.cz/~utx/hardware/Bluetooth_receiver_Enjoy_BT-AU01/#hack_to_silence_idle_noise i added small cap (don't know exactly, but i think it is 15pF, hard to say...) to place marked with yellow oval on Attachment: 2.png. Idle noise gone. Maybe antena performance is worse, but still good enough (range 7~10 meters no problem).

I tried play, next, back, vol+, vol- buttons, all working. Led is flashing with frequency 1~0.5Hz when waiting for connection, ~0.3Hz when connected, fast flashing when connecting, and every ~3seconds tripple flash when calling.

I want to try these commands: http://www.electrodragon.com/w/images/4/4b/BLK-MD-SPK-B_AT_Commands_OVC3860_List.pdf in near future.

[Mark_S]

You were lucky to get your goods from Electrodragon.
I have courier proof of non-delivery and then return of items, and no money or goods back from them.
Looks like scammers to me.

[xpertvis]

I didnt buy from them. I have never said thah. I just search on google for schematics, and found them on their site.
I did buy modules on ebay.

[darmach]

Xpertvis,

I have same BT audio module as you did, did you get yours to work without burning out? .)

I have  a quiestion to you - what is the purpose of those 2 capacitors and 10K resisitor you connected to reset pin?
I have tried using 'button' pins with mine, but it behaves weird - vol +/- acts as next prev, and such things.. I didnt connect anything to reset pin.

[xpertvis]

Hi.

Yes, my BT is working. I am using it from time to time for listening music from phone. I have connected it to my stereo's AUX IN, which i have in shop. I get power from stereo's power supply and lm317 set to 4 volts. So BT is turned on when stere is turned on.
I am not sure, what is a purpose of those 2 capacitors and 10K resisitor connected to reset pin. I have seen it on breakout board for this module. My guess is to prevent reseting BT module in case of unstable power supply (or oscillations from buttons press ?).
I am not using vol+/- and next/prev buttons, but i remember that they worked for me, when i tested it.

I am using it to play music just from phone. Because when i tried play music from windows PC, there was a problem (songs start "chopping" after i hit pause-play, or interrupt playing). But with my phone this module works well and i am actually happy how it works.

[darmach]

Thank you for prompt reply. I have one more question - in my case I also hear high pitch noise - almost not hearable when music is playing, but when the music stops, or Ill turn volume down on my phone its very annoying. Funny thing - its stops completely when I touch/cover antenna part of the pcb with two fingers...

Adding 15 pF capacitor in the place you marked yellow on your schematic didnt help .(

What helps a bit - is when i connect audio out ground with power supply ground - can I do it? Is it safe, what do you think?

Or maybe you would be able to suggest some other solutions?

[victor luu]

I have recently built an amplifier with bluetooth function using this module (XS3868 Ver 2.0).
It work well.
Audio quality is good, not excellent.
Here are some of my experiences with it:
1. Audio Common (pin 1) is 0.9V, don't connect it directly to system ground.
2. Supply voltage should be between 3.6V and 4.2V as mentioned in its datasheet.
If the voltage is 3.3V, an 800Hz annoying noise will appear.
3. Make yourself an SMT-to-TH adapter to reduce the chance of mis-soldering.

Have fun.
 

[xpertvis]

Hi
Sorry for very late reply.
I am not expert, i am just beginner, so everything i am using (like 15pF cap, or whole schematics i shared) i have from other internet sources. They are not my ideas, because i just don't have enough experiences.
But i agree with victor luu, i would not connect supplz and audio GND together.

[magvitron]

Dear all, I know this is a VERY OLD post, but for some one out here doing these sorts of project, there is a neat page for it. http://www.electrodragon.com/w/index.php?title=PKB

[bwack]

I have recently built an amplifier with bluetooth function using this module (XS3868 Ver 2.0).
It work well.
Audio quality is good, not excellent.
Here are some of my experiences with it:
1. Audio Common (pin 1) is 0.9V, don't connect it directly to system ground.
2. Supply voltage should be between 3.6V and 4.2V as mentioned in its datasheet.
If the voltage is 3.3V, an 800Hz annoying noise will appear.
3. Make yourself an SMT-to-TH adapter to reduce the chance of mis-soldering.

Thanks for the advice. It came in handy last night. I have a similar board. S3860M-S V1.2.
I used an external psu, and the gnd in the amplifier was electrically isolated, but when the board is put inside the table radio that I want to modify, then the GND is from same psu and no longer isolated. Good advice there thanks.. I learned that using a couple of caps (220nF), even in series with the AGND, was no problem at all.

The cap on the antenna didn't help, but a tin-foil hat on the antenna did I put a sticky tape on the rear of the pcb near the antenna from the top down to where the groundplane starts. The high pitch buzz was almost gone then.I don't know why, if the foil acts like a highfrequency capacitance, or if the beam is blocked or..  black magic i suppose.

Did you notice with yours that when you put music streamed from phone/pad on pause, then after 5 sec there comes 50Hz noise as if ground has been disconnected ? I solved this (I think) by adding a 2k2 resistor across AGND and audio-out. Now when the bluetooth decoder desides to tri-state or whatever it does, the + and - going to my table radio will be kept together with the resistor. A larger resistor might work. I tried 22k, but that didn't work as well as the 2k2.

So much fun tonight. Made a video
The table radio was salvaged from the dumpsters. £119 worth of working radio, thrown away.. strange...

[bwack]

In the first video, I used an external psu to power the unit and got buzzing, but when I installed the module inside the radio and used the same psu as the radio (obviously) then there was no more buzzing... ground loop ?? Anyway here is an update.

[Hadighorbani]

Hi
this is Hadi
i have this module too
XS3868
i need at command for config that
any one have it?
thank you

[usane]

Hi!

I just received my module. It is 3.0 version. I've found a schematic where the control buttons not connected to 1.8V, instead they are connected to 4.2V VBAT trough a 2k2 resistor. What do you think of it? Like this: http://www.ebay.com/itm/DZ356-Xs3868-bluetooth-stereo-audio-module-control-chip-ovc3860-bluetoot-/151302512846

Hadi. The command list in the 7. post. Xpertvis linked it form Elektrodragon.

[Hadighorbani]

Hi
thank you friend
i see it now.
i try contact with module with windows terminal but i can not type in hyper terminal
when call to my phone the number is show in hyper terminal and some thing like MR
but i can not type at command for control module.
why?

[TheNewGuy]

Hello to all!

I want my desktop speakers to go wireless, so i ordered 2 of xs3686 from AliEx.

The thing is when i was trying to power up the boards, the magic smoke escaped.

So here is what i tried:

First i needed a DC power supply of 3.6-4.2 volts as told by the datasheet, so i soldered wires to pin29 and pin34.
Connected it to my arduino to 3.3v rail after which the smoke came out. I started debugging this and found out i got the ground pin wrong, so i tried again.
This time i actually managed to get it working and even connected via bluetooth. So i got my speaker`s audio jack and touched the modules audio outs with it just to check if the music is transmitted.
All i got was some humming noise and after say 10-20 seconds i lost connection.
Checked Vins on the module and found out they were short-circuited, so the module burned out again... But why?
Can this be that arduino`s 3.3v rail is causing this by means of undervoltaging or do i need dc/dc converter to supply 4v or by a slight chance this has something to do with the quality of the module?

[NightSquirrel]

Hi all,

Referring to the several pinout pictures and schematics that have been posted here, I have some information based on my own experience with this little module. I am using the XS-3868 V3.0 board.

1) the R-C network connected to the RST pin is a reset circuit. It slowly charges the capacitor thru the 10K resistor, causing the RST pin to initially be "low" when the power is applied, and after a while, the capacitor voltage increases to the "rail" voltage, V1.8, and then it stays there. I have to presume that the RST pin is actually active "low" so when power is applied, the OV3860 stays in reset for a bit, then is allowed to run.

I have found, in my case at least, that this isn't necessary. However, it may need to be there for every unit to reliably come up.

2) I too have this "crackle" noise (sounds a bit like static or ignition noise on an old AM car radio) during the quiet/silent parts of the music, but as someone else has observed, just placing one finger on the little antenna trace area quiets it down to zero without affecting playback, at least no effect at the range of a few feet. I will have to experiment with resistor/cap networks to see if a sweet spot can hack this into submission without application of the finger! 

3) this board is meant to integrate a LiION battery charger. That's what the Charge.Pwr pin is for; you put your charging voltage in there, and the chip will then supply charge current to the battery. Now, I didn't intend to use a battery, so I omitted it, but I did put the electrolytic cap as indicated. The cap ends up being the power supply for the whole thing, but your external power should go into the Charge.Pwr pin, not the V.Batt pin. I used 5v coming off a hacked USB cable, for convenience (you can plug it into a cell phone charger, your computer USB port, etc). This seems to work just fine! I think providing anything less than 5 volts to the Charge Power pin, and/or not including the large electolytic cap across V.Batt and ground, will cause the chip to not work correctly.

4) contrary to popular opinion, this little board both transmits and receives BlueTooth! The pause/play, next, previous buttons are part of the Remote Control profile. Implementing these buttons transmits commands back to the music source that you've paired to. However, it is true that this chip will only serve as a "sink" (ie, "receiver") for AADP (Advanced Audio Delivery Profile ?) aka A2DP, aka "playing your music from your phone to this little board".

That's all I know right now. Will post an update if I fix the static-y noise issue during silences.

~~The Night Squirrel 

[ilker.cakir]

Hi,
I found the information posted on this forum to be very useful. Thanks to all who contributed.
Unfortunately I wasn't able to find any schematic or guidance about the microphone inputs. The circuit proposed on those schematics I found didn't work. I have XS3868 V3.0 that I recently ordered. After some trial and errors, I think I managed to get the microphone input working. Although the sound quality is between bad and barely clear, it was possible to transmit sounds from the mic input to my PC which I paired with the device. I was surprised to discover that the mic inputs are not running in the microphone input levels but rather line in levels. I hooked up an mp3 player using a 10nF cap from audio out to mic+ pin and audio ground directly connected to mic- pin at about 5-10% volume output, it was possible to record the sound on the PC with the familiar Audio Recorder program in Windows accessories. If anyone is interested, please let me know, I would gladly draw and upload the schematics to interface a microphone to XS3868 using a TL084 preamp.
Regards,

[amh]

Dear ilker.cakir,
Sorry for contact in last year of 2019, because I currently doing in project which is need an audio transmitter module. I've tried to find the appropriate module and finnaly I find out this module will help my project done fully.

ilker.cakir, could you share us about the schematics of your projects thanksyou..

[ilker.cakir]

Hi, here's update on what I have achieved so far:

1) Attachment schematic.jpg contains the circuit I used.
2) Attachment fully_differential.jpg is another circuit I used when powering this module and the amlipifier from the same symmetric +/-12V source. Please trim the pot for op amp compensation.
3) Photo of PCB produced using Kicad in file pcb.jpg. Black tapes were used to add small pieces of aluminium foil to the sides of the antenna to act as ground plane. At the back of the PCB there is a 18650 liion battery.

Both circuits have produced clear sound without buzz/hum. Some people say audio is not that good, but I disagree. I use Sony MDR-100aap headphones, and I find audio quality very good. One thing to note is, A2DP protocol is running fine on this device however it sounds like there is loss of packets during HFP, which is heard as intermittent pops during speech. Buttons work well with AVRCP. If you want to use Kicad drawings, I would be glad to post them too.

I also developed an application on linux which uses CP2102 module connected on computer USB port, and the other end attached to TX/RX of XS3868. The CP2102 fits on the board through 6 pin female plug.
You may find it here: https://github.com/ilkercakir/XS3868.git I tried to include all AT commands given in the documentation. Just recompile it on your platform.

For questions you may also contact me at [email protected]

Best regards.