Low amplitude while using DMIC input

R.A. Raghuvir1

We are seeing very low amplitude while using the DMIC input for audio recordings, despite setting DMIC1 UL Volume to 29dB. This is on a customer product that has an OMAP4430 running Android Gingerbread, based off of the L27.INC1.13.1 OMAP4 release. Are there any known issues with the audio chain for the DMIC input that would cause very low amplitude in the audio recordings?

Thanks

R.A.Raghuvir

over 13 years ago

0 Israel Cepeda over 13 years ago

TI__Expert 5515 points

That is a know issue that has been resolved in more resent releases, but if you want to stay in this release basically what you have to do is to update the ABE Firmware, APIs and enable extra 12dB gain.

I am attaching the patches to do that, these patches were made within a L27.13.1 kernel release.

0676.0001-Blaze-Firmware-update.txt

0250.0002-Blaze-ABE-API-update.txt

0045.0003-Blaze-fixing-audio-issues-for-app.txt

1524.0004-Blaze-abe-enable-12db-dmic-gain.txt

Please let me know if you have any doubt or issue.

0 Shaan over 13 years ago in reply to Israel Cepeda

Intellectual 450 points

Hi,

I wanted to test the on board digital mic on Blaze Tablet 2 units. The board specification suggests 4 digital Mic connected . Is there some application which can get the samples from these digital microphones.

Regards,

Shantanu Bhaduri

0 Israel Cepeda over 13 years ago in reply to Shaan

TI__Expert 5515 points

Do you mean the 4 mics at same time?. I am not sure but I can take a look, my guess is that it would need to be implemented.

0 Shaan over 13 years ago in reply to Israel Cepeda

Intellectual 450 points

Hi,

Yes I would like to capture from all 4 mic simultaneously. Any help on this is appreciated.

Regards,

Shantanu Bhaduri

0 Shaan over 13 years ago in reply to Shaan

Intellectual 450 points

Hi,

Any help on this.

Regards,

Shantanu Bhaduri

0 Israel Cepeda over 13 years ago in reply to Shaan

TI__Expert 5515 points

I didn't find an app that is able to do that, but you can do it using alsa tools

0 Shaan over 13 years ago in reply to Israel Cepeda

Intellectual 450 points

Hi Israel ,

I was trying out the tiny mix utility to configure the microphone inputs . It gives some MUX options for DMicL0 etc...

Regards,

Shantanu Bhaduri

0 Israel Cepeda over 13 years ago in reply to Shaan

TI__Expert 5515 points

Sorry, I don't get the question.

0 Shaan over 13 years ago in reply to Israel Cepeda

Intellectual 450 points

Israel,

Sorry for missing out the question. What I wanted to know was , whether you were referring to tinymix as the utility to use to capture audio from digital microphones. Is there any documentation or wiki page which explains how to configure the abe to capture from all the 4 digital mic together.

Regards,

Shantanu Bhaduri

0 Israel Cepeda over 13 years ago in reply to Shaan

TI__Expert 5515 points

Hi Shantanu,

tinymix is a tool to get and set the values for the alsa controls, in order to record you should use tinycap application if you are in ICS.

I haven't see any wiki or documentation in internet, I might have to work on something like that to help you, but meantime you may want to take a look at this post: http://e2e.ti.com/support/omap/f/849/p/212255/751304.aspx

Any doubt just let me know

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Low amplitude while using DMIC input