No sound through pmodI2S

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Posted this in a previous thread though was marked as answered so moving this to its own post.

I am for the most part very new to I2S though I am trying to get sound to play from the tx2 through the PmodI2S with no success.

The I2S-DAC seems to be wired correctly and I am getting waveforms through it when audio is played yet no sound is coming through when plugged into anything.

I have tried:

amixer sset -c 1 'I2S1 Mux' 'ADMAIF1'

and

amixer -c tegrasndt186ref sset 'I2S1 Mux' 'MVC1'
amixer -c tegrasndt186ref sset 'MVC1 Mux' 'ADMAIF1'
amixer -c tegrasndt186ref cset name="MVC1 Vol" 50%

With neither working.

I have attached a trace which to me looks OK ?

# tracer: nop
#
# entries-in-buffer/entries-written: 30/30   #P:6
#
#                              _-----=> irqs-off
#                             / _----=> need-resched
#                            | / _---=> hardirq/softirq
#                            || / _--=> preempt-depth
#                            ||| /     delay
#           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
#              | |       |   ||||       |         |
           aplay-9993  [005] ...1 353361.543076: snd_soc_dapm_widget_power: widget=Playback 1 val=1
           aplay-9993  [005] ...1 353361.543084: snd_soc_dapm_widget_power: widget=ADMAIF1 Receive val=1
           aplay-9993  [005] ...1 353361.543087: snd_soc_dapm_widget_power: widget=ADMAIF1 RX val=1
           aplay-9993  [005] ...1 353361.543121: snd_soc_dapm_widget_power: widget=I2S1 Mux val=1
           aplay-9993  [005] ...1 353361.543125: snd_soc_dapm_widget_power: widget=I2S1 TX val=1
           aplay-9993  [005] ...1 353361.543127: snd_soc_dapm_widget_power: widget=I2S1 Transmit val=1
           aplay-9993  [005] ...1 353361.543129: snd_soc_dapm_widget_power: widget=I2S1 Transmit-I2S1 CIF Receive val=1
           aplay-9993  [005] ...1 353361.543131: snd_soc_dapm_widget_power: widget=I2S1 CIF Receive val=1
           aplay-9993  [005] ...1 353361.543133: snd_soc_dapm_widget_power: widget=I2S1 CIF RX val=1
           aplay-9993  [005] ...1 353361.543135: snd_soc_dapm_widget_power: widget=I2S1 DAP TX val=1
           aplay-9993  [005] ...1 353361.543137: snd_soc_dapm_widget_power: widget=I2S1 DAP Transmit val=1
           aplay-9993  [005] ...1 353361.543139: snd_soc_dapm_widget_power: widget=I2S1 DAP Transmit-x Playback val=1
           aplay-9993  [005] ...1 353361.543141: snd_soc_dapm_widget_power: widget=x Playback val=1
           aplay-9993  [005] ...1 353361.543143: snd_soc_dapm_widget_power: widget=x OUT val=1
           aplay-9993  [005] ...1 353361.543145: snd_soc_dapm_widget_power: widget=x Headphone val=1
           aplay-9993  [004] ...1 353438.124645: snd_soc_dapm_widget_power: widget=Playback 1 val=0
           aplay-9993  [004] ...1 353438.124658: snd_soc_dapm_widget_power: widget=ADMAIF1 Receive val=0
           aplay-9993  [004] ...1 353438.124663: snd_soc_dapm_widget_power: widget=ADMAIF1 RX val=0
           aplay-9993  [004] ...1 353438.124684: snd_soc_dapm_widget_power: widget=I2S1 Mux val=0
           aplay-9993  [004] ...1 353438.124690: snd_soc_dapm_widget_power: widget=I2S1 TX val=0
           aplay-9993  [004] ...1 353438.124694: snd_soc_dapm_widget_power: widget=I2S1 Transmit val=0
           aplay-9993  [004] ...1 353438.124698: snd_soc_dapm_widget_power: widget=I2S1 Transmit-I2S1 CIF Receive val=0
           aplay-9993  [004] ...1 353438.124702: snd_soc_dapm_widget_power: widget=I2S1 CIF Receive val=0
           aplay-9993  [004] ...1 353438.124705: snd_soc_dapm_widget_power: widget=I2S1 CIF RX val=0
           aplay-9993  [004] ...1 353438.124708: snd_soc_dapm_widget_power: widget=I2S1 DAP TX val=0
           aplay-9993  [004] ...1 353438.124711: snd_soc_dapm_widget_power: widget=I2S1 DAP Transmit val=0
           aplay-9993  [004] ...1 353438.124715: snd_soc_dapm_widget_power: widget=I2S1 DAP Transmit-x Playback val=0
           aplay-9993  [004] ...1 353438.124718: snd_soc_dapm_widget_power: widget=x Playback val=0
           aplay-9993  [004] ...1 353438.124722: snd_soc_dapm_widget_power: widget=x OUT val=0
           aplay-9993  [004] ...1 353438.124725: snd_soc_dapm_widget_power: widget=x Headphone val=0

I have read through a few similar threads and tried following the steps in the l4t documentation.

I have seen comment on the setup of tegra_pinctrl_reg though not entirely sure what I’m looking at there.

Bank: 0 Reg: 0x02431020 Val: 0x00000400 -> aud_mclk_pj4
Bank: 0 Reg: 0x02431028 Val: 0x00000440 -> dap1_fs_pj3
Bank: 0 Reg: 0x02431030 Val: 0x00000454 -> dap1_din_pj2
Bank: 0 Reg: 0x02431038 Val: 0x00000440 -> dap1_dout_pj1
Bank: 0 Reg: 0x02431040 Val: 0x00000440 -> dap1_sclk_pj0
Bank: 0 Reg: 0x02431024 Val: 0x00708000 -> drive_aud_mclk
Bank: 0 Reg: 0x0243102c Val: 0x01616000 -> drive_dap1_fs
Bank: 0 Reg: 0x02431034 Val: 0x01616000 -> drive_dap1_din
Bank: 0 Reg: 0x0243103c Val: 0x01616000 -> drive_dap1_dout
Bank: 0 Reg: 0x02431044 Val: 0x01616000 -> drive_dap1_sclk

It is also worth noting I am using an auvidea J120 carrier card for the TX2 and not the dev board.

Any help with this would be greatly appreciated.

Many thanks,
Craig

2

Hi Craig,

Are you saying the you see the I2S signals (bit-clock, frame-sync, and data output) from Tegra active when playing the audio file? If so then that would suggest playback from a Tegra perspective is working fine, but for some reason the audio codec is not outputting the audio. You may wish to check the frequency of the bit-clock and frame-sync look correct. If they do then check the codec is powered correctly as it would imply the problem is on the codec side.

Regards,
Jon

3

Hi Jon,

Thanks for getting back to me. Yes from what I can tell there are definite signals being passed into the card when using aplay and targeting tegrasndt186ref,0 on the bclk, lrclk and sdin connectors. I am currently unsure exactly what frequency these are running at as I’ve lost access to my oscilloscope for a couple of weeks :(. I chose the PmodI2S as it was recommended on these forums as possibly working as standard, could it be a potential fault with the card or does this require kernel changes for the codec ?

Many thanks,
Craig

4

Hi Craig,

No kernel changes should be needed and so should be straight forward to connect and use.

Did you see the following comment from the other user? It appeared to be a problem with the pinout on the module itself …

https://devtalk.nvidia.com/default/topic/1032785/jetson-tx2/no-sound-using-i2s-to-cs4344-codec/post/5255680/#5255680

If the signals are active, then as long as the frequencies of the bit clock and frame-sync are supported by the module, I don’t see why this should not work. I have not used one of these myself but this is just based upon reviewing the module documentation and the other users experience.

Regards
Jon