Connection between Bluetooth Headphone and BC127 module


#1

Hi,
I am using BC127 module to stream audio signal from audio in of BC127 to bluetooth headset over A2DP profile . but i got stuck where i cant access microphone signal from bluetooth headset to BC127 audio out. i tried to open HFP profile but its showing error at the time of opening HFP profile. so could you please guide me for the profile setting or any other configuration.
currently i am using melody version 7.1 and i have tested it on Melody version 5.0 RC2 which was a default version when i purchased it. but i dont find v5.0 firmware anywhere on internet to downgrade it from v7.1 to v5.0 so could you please tell me from where should i download it.


Wireless Audio In, Wireless Audio Out with Multiple BC127's
#2

Nikhil,

I am not too sure what you are trying to do? When you have connected the device you want to run the audio with can you send the following commands to the BC127.
version
config
status

Then tell me what you want to do step by step i.e. 1, 2, 3, 4, etc and say where the issue is.

Regards

Matt


#3

hi matt,
thanks for the reply

In order to explain my use case i am divining this scenario into to cases

CASE1: i am pairing wireless bluetooth headset with BC127 and i am giving wired audio input to BC127 through other source and i want to stream this audio signal to the wireless headset

CASE 2: the wireless bluetooth headset that i paired with BC127 has Microphone which takes the audio input and i want to give this audio signal back to BC127 and route them at its audio out pin.

After sending the commands that you told i got following reply:

Version:

Sierra Wireless Copyright 2018<\r>
Melody Audio V7.1<\r>
Build: 1526921906<\r>
<9>Bluetooth addresses: 20FABB06F40E 5AD36C7F4CE4<\r>
<9>Profiles: A2DP AVRCP HFP BLE SPP PBAP MAP TWS<\r>
<9>Codecs: SBC<\r>
OK<\r>

CONFIG:

AUDIO=0 0<\r>
AUDIO_ANALOG=15 15 1 OFF<\r>
AUDIO_DIGITAL=0 44100 64 100A00 OFF<\r>
AUTOCONN=0<\r>
AUTO_DATA=OFF OFF<\r>
BALANCE=100 100<\r>
BATT_CONFIG=OFF 145 4250 1500 150<\r>
BC_SMART_CONFIG=68E3 28F0 89F7 D93C ON<\r>
BEACON_DATA=0 00 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF 04 D2 16 2E EE<\r>
BLE_CONFIG=0 OFF 80 ON<\r>
BLE_CONN_PARAMS=128 12 24 40 0 400 100 400 400 64 400 400<\r>
BT_STATE_CONFIG=0 0<\r>
BT_VOL_CONFIG=A 60 10 1<\r>
CLASS_1=OFF<\r>
CMD_TO=20<\r>
COD=240404<\r>
CODEC=0 OFF<\r>
DEEP_SLEEP=OFF<\r>
DEVICE_ID=0001 0002 0003 0004 0005 0006 0007 0008<\r>
ENABLE_BATT_IND=ON<\r>
ENABLE_LED=ON<\r>
ENABLE_SPP_SNIFF=OFF 0 0 0 0 0<\r>
GPIO_CONFIG=ON 0<\r>
HFP_CONFIG=OFF ON OFF OFF OFF OFF<\r>
HIGH_SPEED=OFF OFF<\r>
LOCAL_ADDR=20FABB06F40E 5AD36C7F4CE4<\r>
MAX_REC=2<\r>
MM=OFF OFF 0 OFF OFF OFF OFF OFF<\r>
MUSIC_META_DATA=OFF<\r>
MUSIC_OLD_AVRCP=OFF<\r>
NAME=BC-06F40E<\r>
NAME_SHORT=BC06F40E<\r>
PIN=0000<\r>
PROFILES=2 0 2 0 2 3 2 1 0 0 2 0<\r>
REMOTE_ADDR=000000000000<\r>
SPP_UUID=00 00 11 01 00 00 10 00 80 00 00 80 5F 9B 34 FB <\r>
SSP_CAPS=3<\r>
TWS_CONFIG=OFF 1 2<\r>
UART_CONFIG=9600 OFF 0<\r>
USB_HOST=OFF<\r>
VREG_ROLE=1<\r>
OK<\r>

STATUS

STATE CONNECTED[1] CONNECTABLE[OFF] DISCOVERABLE[OFF] BLE[IDLE]<\r>
LINK 10 CONNECTED A2DP 1258562D390F SUSPENDED SBC SRC 0<\r>
LINK 11 CONNECTED AVRCP 1258562D390F PLAYING<\r>

To open a connection between bluetooth headset i followed this command

Step 1: OPEN 1258562D390F A2DP // to open A2DP connection between headset and BC127

REPLY:

PENDING<\r>
OPEN_OK 10 A2DP 1258562D390F<\r>
ROLE_OK 1258562D390F M<\r>
OPEN_OK 11 AVRCP 1258562D390F<\r>
ABS_VOL 11 84

STEP 2: OPEN 1258562D390F HFP // to open HFP Profile
Reply:
PENDING<\r>
OPEN_ERROR HFP <\r>
<\r>

since i got this error i cant access HFP profile to take the input from the mic of wireless headset.
earlier i tried to do this in Melody version 5.0 RC2 and it was working, so could you please tell how can i get that version .dfu file if this version 7.1 does not work at all.


#4

Nikhil,

Still not 100% clear but for step 2 above are you sure 1258562D390F has a HFP to connect to?

So a couple of questions,

  • the two cases above are they separate or you want to achieve this simultaneously?
  • You want both audio streams in and out to go via the analog audio?

If you are running say A2DP as a source taking the audio in over the analog interface (assuming this) you cannot then route audio coming into the unit over HFP or even over any other audio interface, the unit can only handle one audio stream to an external interface at a time.

Regards

Matt


#5

hi matt,
i am sure that this bluetooth headset has HFP because i have tested it by connection to my mobile phone.

  • i want the audio stream in and out simultaneously

Could you please tell me where should i get the firmware Version 5.0 RC2 because its working for my requirements .
i got this firmware when i purchased it but to check with the new features i have upgraded it to 7.1 but right now i don’t have .dfu firmware v5.0 to downgrade it.


#6

Hi,
It looks like you should configure the BC127 as an Audio Gateway (AG) for the HFP profile.
i.e. enable AGHFP in PROFILES configuration, then use OPEN AGHFP.
Regards,


#7

Nikhil,

Re the question about firmware 5.0 RC it is so old it is pre Sierra Wireless and as a result it needs to be retrieved, you are going to need to ask your commercial channel for that.

Regards

Matt


#8

Hi Matt,

I got the same problem here.
I can stream audio to the headset but can not get decent audio back.

My BC127 does connect to the headset on AGHFP.
I need to use CALL 12 INCOMING 1 to get the headset switch to HFP, then it sends something like audio to the BC127 but the quality is extremly bad. Worse than a phone line.

Can you let me know if you have more succes with the older firmware?

Regards, Ronald


#9

Hi Ronald,

As per my knowledge If you are using HFP profile then audio quality becomes poor because it uses lower sampling rate. but you can stream audio in good quality if you use A2DP profile but its only one way communication.

I followed this command to open A2DP connection
OPEN bluetooth-id A2DP to open A2DP profile and then use MUSIC 10 PLAY to start audio stream .

and to start HFP (for Melody Version 6.1.5)

SET PROFILES=2 2 0 2 2 1 2 1 0 0 1 0 //one time setting
SET HFP_CONFIG=OFF ON OFF OFF OFF
WRITE
RESET

MUSIC 10 STOP //if A2DP Connection is open
CALL 12 OUTGOING 1 //to start call
CALL 12 END //to stop call

i hope this could help to improve the audio quality.

Regards,
Nikhil


#10

hi Nikhil,

THANK YOU VERY MUCH, it is working as it should!!!
Only a small addition, in the set profiles I had to add an extra OFF
This is what i did:

set profiles 2 2 0 2 2 1 2 1 0 0 1 0

OK

SET HFP_CONFIG=OFF ON OFF OFF OFF OFF

OK
WRITE

OK
RESET

Sierra Wireless Copyright 2018
Melody Audio V7.1
Build: 1526921906
Ready
OPEN 97B8E2295CE2 A2DP

PENDING
OPEN_OK 10 A2DP 97B8E2295CE2
ROLE_OK 97B8E2295CE2 S
OPEN_OK 11 AVRCP 97B8E2295CE2
OPEN 97B8E2295CE2 AGHFP

PENDING
OPEN_OK 12 AGHFP 97B8E2295CE2
REMOTE_VOLUME 12 F
MUSIC 10 STOP

OK
CALL 12 OUTGOING 1

OK
SCO_OPEN 12
CALL_OUTGOING 12

I have now full duplex audio, just as I wanted.
The audio quality however is still low, much lower than streaming over A2DP.
Can that be a result of the build-in echo canceller? i notice a threshold if I turn down the audio volume at the input of the BC127. it mutes and comes back when I turn it up.

Regards,

Ronald


#11

Hi Matt,

I just ordered the BC127 Breakout board from Digikey for a school project. Im wondering if theres a way to route audio digitally from a USB-C port of a phone to the digital inputs of the module for Bluetooth Transmission. Im guessing I would have to configure the BC127 in Source mode. Im not sure how to route digital audio. Lastly, I saw that the modules have the dual A2DP source feature, I hope to be able to test that. Thanks