Tdm mic array

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

Hi ,

I am using jetson nano production module . I enabled i2s4 and it can record stereo Adafruit MEMS as follows

I did make i2s4 stereo Adafruit I2S MEMS microphone working by doing following command
amixer -c tegrasndt210ref cset name=‘ADMAIF1 Mux’ I2S4
arecord -D hw:tegrasndt210ref,0 -r 48000 -f S32_LE -c 2 -d 10 test.wav.

I also tried to connect the 4 channel tdm mic arrary on the same i2s4 pin. but i can not make recording working.
amixer -c tegrasndt210ref cset name=‘I2S4 codec frame mode’ dsp-a
arecord -D hw:tegrasndt210ref,0 -c 4 -r 48000 -f S32_LE cap.wav

My understanding is that i dont have to change the i2s4 pin configuration as it is alreayd enabled because i can record Adafruit stereo mic already. right ? what is the correct tdm configuration , I attaching the mic datasheet and mic array spec .

Thanks

https://www.cdiweb.com/datasheets/notwired/ds-nw-aud-ics52000.pdf which is using invensense mic
https://www.cdiweb.com/datasheets/invensense/ds-000121%20ics-52000%20data%20sheet%20v1%201.pdf

THanks

3

Hello!

By default the I2S4 signals are not enabled on the 40-pin header. The Adafruit MEMS mic is supported and can be enabled by …

sudo /opt/nvidia/jetson-io/config-by-hardware.py -n "Adafruit SPH0645LM4H"
sudo reboot

For more details see …

https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fhw_setup_jetson_io.html%23

Regards,
Jon

4

just to confirm the I2S4 pin configuration is the same for i2s mode and tmd mode . is it correct ?

as i already get Adafruit mic working that mean i2s4 configuration is okay right >> now the problem is that i can reacord with another tdm micphone

5

Hello!

Yes the same pinmux settings are fine for both I2S and TDM modes.

Jon