[ADAU1451] I2S microphone configuration with AEC algorithm

SigmaDSP & SigmaStudio pedro_albergaria Jun 14, 2021 00:00 2 replies Original on forum ↗

pedro_albergaria Question

Jun 14, 2021 00:00

Hello all,

I am not experienced in audio signal processing and I have never worked with SigamaStudio or any Analog Devices' DSP, therefore I am having some difficulties.

I am using the HiFiBerry DAC+ DSP platoform that has the ADAU1451 DSP. For my project, I have 2-channel standard I2S microphone that support sampling rates from 32kHz to 64kHz. To connect the microphone to the HiFiBerry platform, I am using SDATA_IN1 and SDATA_OUT1 Serial Data Pins. These pins map to the input cells 16 and 17 on the SigmaStudio, therefore I have two inputs and output signals for the left (16) and right (17) channels.

According to the SigmaStudio's Acoustic Echo Cancellation (AEC) project (presented in this link), there is only one microphone input to the algorithm. How can I (if possible) merge the left and right channels into one signal for the AEC algorithm? If this is not possible, what is the alternative solution?

Thank you in advance and best regards.

Audio Signal Processors

adau1451

i2s

SigmaDSP Audio Processors

aec

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DaveThib Reply

Jun 18, 2021 00:00

Hello Pedro,

First you do not have to use SDATA_OUT1 serial port for the microphone input. That is a serial output port, you will need this to send the data out to some DAC that I assume is on this board.

You can just sum the data from the two microphone channels into one signal and route that into the AEC input.

So this is what you would do:

You might have a problem if the two mics are very distant from each other. They would pick up different signals and different echos. So that might be a problem. In that case I suggest you use only one mic. If the mics are only a few inches away from each other then I do not think this will be an issue.

Dave T