I2S microphone record on Jetson nano dev kits

Hi ,

I connected the SPH0645 i2s mic on the J41 header .
Pin1 = 3V
I2S_4_LRCK - PIN 35
I2S_4_SDIN - PIN 38
I2S_4_SCLK - PIN 12

amixer -c tegrasndt210ref cset name=‘ADMAIF1 Mux’ I2S4
arecord -D hw:tegrasndt210ref,0 -r 48000 -f S16_LE -c 1 -d 10 test.wav

i am not able to record the audio with above command .

sudo grep dap4 /sys/kernel/debug/tegra_pinctrl_reg

Bank: 1 Reg: 0x70003144 Val: 0x00000054 -> dap4_fs_pj4
Bank: 1 Reg: 0x70003148 Val: 0x00000054 -> dap4_din_pj5
Bank: 1 Reg: 0x7000314c Val: 0x00000054 -> dap4_dout_pj6
Bank: 1 Reg: 0x70003150 Val: 0x00000054 -> dap4_sclk_pj7

does this mean default pin is not configured as i2s function ? I am not able to chagne dtb file . I am using R32.2.1 l4t

Could you check and let me know how to override the pin config in dtb and update mew dtb?


The above configuration for the I2S4/DAP4 pins shows the output-enable is disabled for all of these pins (bit 4 is set). These pins default to being GPIO as well (although we cannot confirm from the above register dump). The recommended approach is to rebuild the bootloader as described in this thread …


We are working to improve this.



I just wanted to let you know that we have release JetPack 4.3 (L4T 32.3.1) and we now have a tool included to assist with the reconfiguration of the pins exposed by the 40-pin header so that you no longer need to rebuild and reflash. Please see the following:




Just to let you know that we have identified an issue with the Jetson.IO tool on Nano when updating Nano using SD card image. However, there is a simple fix availabe. Details are here: