ADAU1467 eval and 6 I2S microphones

Martmarttoo Question

Aug 28, 2023 00:00

Dear developers,

I am trying to connect 6 digital microphones to the adau1467 evaluation board. The microphones are all INMP441 on a breakout board.

They are connected to SDATA, LRCLK and BCLK at IN0 and IN3 at J8 and IN1 at J5. L/R of the mic's are connected in pairs to 3.3v and 3 to 0v, so I have 3 stereo sets.

The first test to try is confirming that the microphones work as intended and I failed already.

This is my setup

The serial inputs are configured

Here is where I get confused, only 2 inputs for 4 channels at the adau1467?

And the multipurpose tab is configured like this

I measure 3.3v at the vdd of the microphones,3.07MHz at SCK/BCLK, no signal at WS/LRCLK and SD/SDATA.

Can someone guide me in the right direction?

Thank you so much!

Audio Signal Processors

Audio Products

microphone

adau1467

i2s

EVAL-ADAU1467Z

SigmaDSP Audio Processors

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ADIApproved Reply

Aug 28, 2023 00:00

ADI North America will be on summer shutdown starting August 24, 2023; perhaps another community member can assist you until our return on September 5th.

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Harishgowtham Reply

Aug 29, 2023 00:00

Hi Martmarttoo

This microphone INMP441 is an I2S microphone. You can directly use them into the serial port of ADAU1467.The digital mic input block which you are using is for PDM mic input but not for an I2S input. Here I will attach the hardware connections reference and register settings for connecting I2S mic into the DSP. I will also attach a project where everything is configured.

This stereo mic should be connected to one of the serial input ports. Let's say Serial IN0. So, you have to use 3 ports for three stereo mics respectively.

Set all the respective serial input ports like above.

Above is the I2S timing diagram which matches with the above serial port configuration.

All the stereo outputs of ADAU1467 eval board is enabled in the attached project and the serial input ports are all set.

I2S microphone.dspproj

Regards,

Harish