Issue when connecting I2S microphone to Clock and sampling frequency channels

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
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1

Hello,

I have configured my jetson nano developer kit to have the I2S pins enabled, this has worked and I have verified this by reading both the FS and SCLK pins using an oscilloscope. Photos of the output can be seen below. Note that the scale is 1 volt per division.

IMG_3916
IMG_39161920×2560 229 KB

IMG_3917
IMG_39171920×2560 200 KB

My issue comes form when I connect the microphone to these channels, the data in the channels changes to look like the 3rd image and the board’s output from these pins drops very low. The microphone I am working with is an INMP441 (https://invensense.tdk.com/wp-content/uploads/2015/02/INMP441.pdf).

What is likely the cause of this ? I think that is may be the current requirement of the microphone being 1.4mA is this likely to be the case.

IMG_3919 2
IMG_3919 21920×2560 204 KB

3

Hi,
Most likely some connection issue, can you provide info on the voltage supply range to MIC and also what all pins in the MIC part are GND.

I believe the 3rd image is SDOUT from MIC. How about the clock signals when you connect MIC to Tegra I2S.

4

Hi,

Thanks for the reply. The 3rd signal is what the clock and sampling frequency singals look like after I connect them to the microphone, the serial data line is not shown here.

The voltage supply to the mics here is the 3.3v pin.

Thanks

5

Thanks for the clarification.

Can you give a try with 1.8V supply to Mic and also confirm if the MIC part GND pins are properly connected to ground.

6

Hi,

I’m not sure what I had done as I had this issue with 3 different microphones, I fully redid my entire setup and this solved the issue. If anyone else faces a similar issue, the setup that worked for me was a pin header an 6 core screen wire wired directly to the microphone, I assume I had maybe cooked the last microphone that had an identical setup.

Thanks for trying to help Mkumard, but looks like this was entirely a hardware issue and as a result purely my fault.

Thanks again.

7

Hi lucafaccenda22,
It is a great news to hear. Happy that issue got resolved.

Good Luck!

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