Xavier Audio Panel Header (J511) connection to microphone

I’d like to get a microphone working via the Audio Panel Header (J511), but have had no luck so far.
Is this possible? From the Xavier Dev Kit Carrier Board Spec:

Table 14.  AudioPanel Header Descriptions 

Pin# Signal_Name  CODEC_Name  Usage/Description  Type/Dir
1    IN1P         IN1P        Mic #1             Output
2    GND          ----        Ground             Ground  
3    IN2P         IN2P        Mic #2             Output
4    AUD_GPIO4    GPIO4       Audio Dongle Det   Input
5    AUD_HPOR     HPO_R       HeadPhone Right    Input
6    AUD_MIC_JD   MIC_IN_DET  Mic Detect         Input
7    SENSE_SEND   NA          Pulled to GND      NA
8    KEY          NA          NA                 NA
9    AUD_HPOL     HPO_L       Headphone Left     Input
10   AUD_HP_JD    GPIO3       Headphone Detect   Input

The Type/Dir column direction seems reversed to me.?.?.?

Anyway, do I want to use IN1P or IN2P?
Do I need to do anything with Pin#6 or any other pin? (Tie high, low?)
Is any software setup required besides what is in Ubuntu Sounds applet?

Thanks, tonyvr

About the font: It is variable for most text, but if you use the pencil icon in the upper right (hover the mouse over the quote icon if you don’t see it), then you can edit. Highlight the table 14 content, then click the “code” icon (looks like “</>”) and it’ll preserve whitespace and use fixed width font.

Thanks linuxdev – much better.

Hi, in the Type/Dir column, Output is to Audio Panel Header. Input is from Audio Panel Header. Bidir is for Bidirectional signals.

Pin #6 is tied to MICBIAS1 as you can see in Jetson_Xavier_Developer_Kit_Carrier_Board_Specification.pdf.

Hi Trumany,

Thanks for your response.

The copy of the Jetson_Xavier_Developer_Kit_Carrier_board_Sepcification.pdf that I just downloaded shows that pin 6 is what I have in my table:

AUD_MIC_JD, MIC_IN_DET, Jack/Microphone detect pin, Input

Whatever it is, I still need answers for the following questions:

Do I want to use IN1P or IN2P?
Do I need to do anything with Pin#6 or any other pin? (Tie high, low?)
Is any software setup required besides what is in Ubuntu Sounds applet?

Thank you

You can find the default reference design in schematic of P2822 in DLC.

Also you can find more information in datasheet of codec, ALC5658.

Hi Tonyvr,

Yes looking at the Xavier Carrier Board spec for the audio panel header some of the type/direction descriptions do appear reversed. I will see if we can get this corrected.

With regard to your questions …

  1. You should use the IN1P signal. Per the Xavier device-tree [0], under ‘nvidia,audio-routing’ this is used for microphone.
  2. I did ask if it was necessary to connect pin 6 and we don’t believe that it should be necessary. I have not tested this myself, however, just for your information I test with an off-the-shelf front panel [1]. Note you only need to connect the 9-pin audio cable and not the USB3 connectors.
  3. No there should not be any other software setup needed. If you run into any issues please let us know so that we can assist further.


[0] https://nv-tegra.nvidia.com/gitweb/?p=device/hardware/nvidia/platform/t19x/stardust-dts.git;a=blob;f=common/tegra194-audio-p2822-0000.dtsi;h=b936b70a1af6d773a32837cd56a3f119442ac951;hb=l4t/l4t-r31.1
[1] https://www.amazon.co.uk/gp/product/B013QSTTUO/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Thank you very much for the info Jon,

I just got a new mic board with Auto-gain Control from Adafruit, so I will try again and let you all know how it worked out.


Hi Jon,

I found that you definitely need to tie pin 6 (AUD_MIC_JD) to ground to get the microphone to work.

Thanks again for the help.


Hi Tonyvr,

Thanks for the feedback.


Are there any specific requirements for the Mic ?
Do you need the amplifier board ? or will just an electret mic work ?
Which code are you using to work with the Audio data ?


I am not aware of any specific requirements for the mic. Looking at the front panel board I am using [0], it appears to just connect the mic jack to the mic input. However, as Tonyvr pointed out it appears than pin 6 on the header needs to be grounded.

For capturing audio from the mic, I just test with the ALSA arecord utility.


[0] https://www.amazon.co.uk/gp/product/B013QSTTUO/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1


I first used a simple unamplified mic that I cut from an old headset. This worked OK except that I had to have it right near my mouth. (same with the little USB mic I tried).

I recently received this amplified mic:


I verified that it can pick up my voice from normal monitor viewing distance, although there was a high level of background noise as well. I will be playing with it more this weekend.


“high level of background noise”

the background noise comes from the mic touching a surface, a cloth wrapped several times should improve that considerably. maybe a low pass filter would also improve the result.

What about speakers ?
do we have to run an amplifier from the headphone output ?
does the HDMI port have audio ?


According to the carrier board specification for the Xavier development kit, the headphone outputs can drive powered-speakers and so would imply that some amplification is needed.

Yes the HDMI port does support audio and this soundcard can be selected under the Ubuntu desktop settigs.


Can I go for this basic looking audio panel?


You can try it, there is a chance it will work as it does list ‘HD Audio’ support. I have not tested this and there are no reviews, so I have no idea if this is any good.


Thank you I will try it tmrw and let you know.