AM5728: CMB interface issue

Janardan M

Part Number: AM5728
Other Parts Discussed in Thread: PCM1864

Hi ,

In my present project I am working on interfacing Circular Microphone Board(CMB) with GPEVM AM572x sitara processor.

I am using McASP7 lines as audio in lines, I tested the interface on 2 microphones and is working as expected.

The audio data is passing through BF, AEC , MSS algorithms and I am able to listen clean audio out through audio out jack on EVM.

I am able to access 2 McASP7 Data in port pins on EVM, hence I want to interface 4 microphones from CMB.

I am configuring to work with 2 serializers, pin mux for both pins are proper. Rx, Tx, signal processing buffer lengths seems to be proper.

But when I test the interface of 4 microphones with AM572x through 2 McASP7 serializers, I am unable to listen to clean audio, it is not completely mute,

I am able to listen the distorted audio, there is no background noise but audio is distorted, what would be possible issue?

I am using K2G interface with CMB as reference code.

Thanks in advance,

-Janardan M

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Janardan,

The RTOS team has already informed you that there is no support for CMB in the AM57x RTOS SDK: e2e.ti.com/.../2573630

0 Janardan M over 7 years ago in reply to Biser Gatchev-XID

Expert 1115 points

Hi Biser,

I am aware that there is no support for CMB on AM572x RTOS SDK, hence I configured CMB through I2C and CMB is responding, I explicitly included VoLib and AER libraries, as mentioned I am able to interface 2 microphones on CMB with AM572x and is working as expected.

Now I am trying to use 4 microphones on CMB, I need support on that.

Thanks,
Janardan

0 Lalindra Jayatilleke over 7 years ago in reply to Janardan M

TI__Mastermind 30365 points

Janardan,

Do you have the PCM1864 on the CMB correctly configured for 4 mics (I2C config in your code would need to take care of the 2nd PCM1864 init)

Lali

0 Janardan M over 7 years ago in reply to Lalindra Jayatilleke

Expert 1115 points

Hi Lali,

Both PCM1864 Ic's on CMB is configured properly, I am using Data3 and data4 lines coming out of CMB, if I test the 2 lines independently(2 mics at a time) then the output is as expected, but when I test 2 lines together then the audio heard is noisy.

Also, when I probe I could observe data on both DATA3 and DATA4 line.

Thanks,
Janardan M

0 Janardan M over 7 years ago in reply to Janardan M

Expert 1115 points

Hi lali,

I could fix the issue, now I am able to listen to audio from all the 4 microphones.

Thanks,
Janardan

0 Lalindra Jayatilleke over 7 years ago in reply to Janardan M

TI__Mastermind 30365 points

Janardan,

That's great! What was the issue?

Also, how did you connect the CMB to the AM57x GPEMV? did you create a special breakout card?

Lali

0 Janardan M over 7 years ago in reply to Lalindra Jayatilleke

Expert 1115 points

Hi lali,

I was using buffer format wrongly at receive end, i was using multislot semi interleaved 1 instead of multislot semi interleaved 2, once I fixed it I am able to listen to better audio.

Yes, I have my own breakout card which is connected to P12 connector of LCD board, from there I am able to access McASP 7 lines and I2C lines as well.

Thanks,

Janardan

0 Janardan M over 7 years ago in reply to Janardan M

Expert 1115 points

Hi Lali,

I want to generate the Beam Forming Filter coefficients for 4 microphones, in bfgui what am I supposed to feed in for distance between microphones for circular microphone board.

Thanks,

Janardan

0 Lalindra Jayatilleke over 7 years ago in reply to Janardan M

TI__Mastermind 30365 points

Janardan,
Please create a new thread for the above question.

Lali

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AM5728: CMB interface issue