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?
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.
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?
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 …
You should use the IN1P signal. Per the Xavier device-tree [0], under ‘nvidia,audio-routing’ this is used for microphone.
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.
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.
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.
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 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.
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.
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.