a2dp sink noise

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FeTa_4356966
Level 3
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Distributor - Zenitron(GC)
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Hello,

I tested the A2DP sink function using "snip.bt.a2dp_sink" in WICED-Studio-6.4.

Program to CYBT-343026-01, connect the I2S output to the DAC (NXP UDA1334A), and output to the headset for playback.

The sound output has a noise, once every four seconds, pronounced like "po".

I have tried programming to CYW920706WCDEVAL and the situation is the same.

Is there any experience in solving this? What parameters can be improved?

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1 Solution
AnjanaM_61
Moderator
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5 comments on KBA First comment on KBA 5 questions asked

Hi,

Can you please confirm the sampling frequency DAC is tuned to ?

Please note the frequencies supported by 20706 is 44.1 & 48 KHz as mentioned here: PCM/I2S Clock setting in CYW20706

Can you please check and confirm?

Regards,

Anjana

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5 Replies
AnjanaM_61
Moderator
Moderator
Moderator
5 comments on KBA First comment on KBA 5 questions asked

Hi,

Can you please confirm the sampling frequency DAC is tuned to ?

Please note the frequencies supported by 20706 is 44.1 & 48 KHz as mentioned here: PCM/I2S Clock setting in CYW20706

Can you please check and confirm?

Regards,

Anjana

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FeTa_4356966
Level 3
Level 3
Distributor - Zenitron(GC)
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Hi,

I tried to switch A2D_SBC_IE_SAMP_FREQ_44 and A2D_SBC_IE_SAMP_FREQ_48, only 44.1KHz can be played.

I think it is working at 44.1kHz.

I tested the BT_AUDIO_A2DP_SBC_MAX_BITPOOL parameter and I adjusted it to 16~40.

The noise is changed once every four seconds and becomes non-periodic noise (about 3 noises in 1 minute).

/*****************************************************************************

*   codec and audio tuning configurations

****************************************************************************/

/*  Recommended max_bitpool for high quality audio */

#define BT_AUDIO_A2DP_SBC_MAX_BITPOOL   53

/* Array of decoder capabilities information. */

wiced_bt_a2dp_codec_info_t bt_audio_codec_capabilities[] =

{

    {

        .codec_id = WICED_BT_A2DP_CODEC_SBC,

        .cie =

        {

            .sbc =

            {

//                (A2D_SBC_IE_SAMP_FREQ_44 | A2D_SBC_IE_SAMP_FREQ_48),    /* samp_freq */

                (A2D_SBC_IE_SAMP_FREQ_44),                                /* pairing success and playback */

//                (A2D_SBC_IE_SAMP_FREQ_48),                              /* cannot pair device */

                (A2D_SBC_IE_CH_MD_MONO   | A2D_SBC_IE_CH_MD_STEREO |

                 A2D_SBC_IE_CH_MD_JOINT  | A2D_SBC_IE_CH_MD_DUAL),      /* ch_mode */

                (A2D_SBC_IE_BLOCKS_16    | A2D_SBC_IE_BLOCKS_12 |

                 A2D_SBC_IE_BLOCKS_8     | A2D_SBC_IE_BLOCKS_4),        /* block_len */

                (A2D_SBC_IE_SUBBAND_4    | A2D_SBC_IE_SUBBAND_8),       /* num_subbands */

                (A2D_SBC_IE_ALLOC_MD_L   | A2D_SBC_IE_ALLOC_MD_S),      /* alloc_mthd */

                BT_AUDIO_A2DP_SBC_MAX_BITPOOL,                          /* max_bitpool for high quality audio */

                A2D_SBC_IE_MIN_BITPOOL                                  /* min_bitpool */

            }

        }

    },

};

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Hi Felix Tang,

Can you please confirm if the noise issue is still there?

We had tested the same A2DP sink example with another codec as mentioned in the blog :WICED Studio Bluetooth Forums

But there was no noise issue.

I think you may have to check on the codec configurations which you are using.

Thanks,

Anjana

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FeTa_4356966
Level 3
Level 3
Distributor - Zenitron(GC)
50 sign-ins 10 likes given 25 sign-ins

Hi Anjana,

The noise problem exists on CYW920706WCDEVAL and CYBT-343026-01.

I tried to move the original a2dp_sink to 20719-B1_Bluetooth (EVB: CYW920719Q40EVB_01) and the noise problem disappeared.

===================================================

I want to use the Azurewave AW-BT304(CYW20719) instead.

However, there are distinctions between CYW20719-B1 (wiced) and CYW20719-B2 (modus). With CYW20719-B2 developed by MODUS, is there an example of "a2dp sink"?

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Hi Felix Tang,

I am sorry , unfortunately we are not promoting CYW20719 B1/ B2 for Audio profiles. Only A2DP source is supported.

Our Audio solutions are CYW20706 and CYW20721 modules .

Please contact your local FAE for the details.

Thanks,
Anjana