Beaglebone Audio Cape Rev B audio Input

Hi

I’ve acquired an Audio Cape Rev B http://elinux.org/CircuitCo:Audio_Cape_RevB for my Beaglebone Black.

Following the instructions I was able to make it work. The audio playback is working pretty well. However, I cannot test the audio input. I saw that it is a line level input (line in), so it cannot be connected to a regular microphone.

I want to test it through an echo scheme. I will produce some sound through q source (connected to the line in input of the cape) and check the response in the audio output, through an earphone.

I tried to connect the cape line in to the earphone output of an old cellphone through a male male jack cable (I saw in some forums that the line level is similar to the earphone output of some appliances, apart from the impedance difference.). Unfortunately, it didn’t work.

The interesting thing is that when the cable is connected to the cape audio input and the other connector is unplluged, I can hear the noise from static, similar to an unplugged to the amplifier electric guitar .

Can someone suggest me a simple form to test the audio input?

Regards.

Hi

I’ve acquired an Audio Cape Rev B http://elinux.org/CircuitCo:Audio_Cape_RevB for my Beaglebone Black.

Following the instructions I was able to make it work. The audio playback is working pretty well. However, I cannot test the audio input. I saw that it is a line level input (line in), so it cannot be connected to a regular microphone.

I want to test it through an echo scheme. I will produce some sound through q source (connected to the line in input of the cape) and check the response in the audio output, through an earphone.

I tried to connect the cape line in to the earphone output of an old cellphone through a male male jack cable (I saw in some forums that the line level is similar to the earphone output of some appliances, apart from the impedance difference.). Unfortunately, it didn’t work.

The interesting thing is that when the cable is connected to the cape audio input and the other connector is unplluged, I can hear the noise from static, similar to an unplugged to the amplifier electric guitar .

Can someone suggest me a simple form to test the audio input?

I don’t have the Audio Cape, but I do have a TLV320AIC3106EVM connected to my BBB and it works fine. You may want to try the following command:

arecord -r 44100 -c 1 -f S16_LE -t wav -vv -d 25 example.wav

This will show you a bar graph in the terminal so you can see the input levels. I would just connect the output from you phone to the line input of your audio cape. In another terminal, run amixer to adjust the input levels.

Regards,
John

It seems that I messed with the amixer parameters. Now I can not even
hear from the speaker test. Is there a way of reseting alsa
parameters, not only the general audio volume?

I saw something like
alsactl restore -P
and removing '/var/lib/alsa/asound.state
but it didn't work for parameters specifically to the DA830 EVM.

Why the audio cape is recognized as a DA830 EVM?

I suspect that the audio input is not working due to one of that parameters.

Regards, Raphael.

It seems that I messed with the amixer parameters. Now I can not even
hear from the speaker test. Is there a way of reseting alsa
parameters, not only the general audio volume?

I saw something like
alsactl restore -P
and removing '/var/lib/alsa/asound.state

After this, you need to restart alsa-utils. Also make sure you don¹t have
.asoundrc in your home folder.

but it didn't work for parameters specifically to the DA830 EVM.

Why the audio cape is recognized as a DA830 EVM?

The TLV320AIC3xxx codec is recognized as a DA830 EVM. If you look in the
audio cape DTS file, you will see ti,model = ³DA830 EVM².

Regards,
John

It seems that I messed with the amixer parameters. Now I can not even
hear from the speaker test. Is there a way of reseting alsa
parameters, not only the general audio volume?

I saw something like
alsactl restore -P
and removing '/var/lib/alsa/asound.state

To restart alsa-utils, do the following:

invoke-rc.d alsa-utils restart

Regards,
John

in my use of audio and this card from the console I found alasmixer much easier to use. I just went through and set all the levels to 100% and it works well. Try using alsamixer it should get things fixed up in an easy and intuitive way. F1 and the man page cover the controls.

Eric

in my use of audio and this card from the console I found alasmixer much easier to use. I just went through and set all the levels to 100% and it works well. Try using alsamixer it should get things fixed up in an easy and intuitive way. F1 and the man page cover the controls.

This is true, and if you run alsamixer in a SSH session, it looks much better than in a tty console like minicom.

Regards,
John

Hey folks,

Thank you all for the support so far. I did it. Now it is working.

It's a shame to admit but It was the capture sound level that was too
low. I used alsamixer and entered in the capture tab (F4) and put all
the inputs in the highest level.

Regards,

Hi John,

Can you please send through details on how you connected the TLV320AIC3106EVM to the BBB - I am trying to do the same thing.

Cheers,
Evan

http://elinux.org/CircuitCo:Audio_Cape_RevB
schematics and everything there

Thanks, I also managed to subsequently dig this up http://article.gmane.org/gmane.comp.hardware.beagleboard.user/63099.

I’ll probably try the same thing but inject the 1.8V from my bench supply.

Thanks, I also managed to subsequently dig this up http://article.gmane.org/gmane.comp.hardware.beagleboard.user/63099.

I’ll probably try the same thing but inject the 1.8V from my bench supply.

Look at /arch/arm/boot/dts/am335x-bone-common-pinmux.dtsi line 220. These are the pins used to connect to the TLV320AIC3106EVM. The table below shows how I got this working.

BBB TLV320AIC3106EVM LTC3603
P9 J17 J16 J15 J5
1 GND 4 5 GND GND
3 3V3 9 3V3 2 VOUT_EN
5 VDD_5V0 3 +5V VIN
7 SYS_5V0
10 SYS_RESETN 14 RESETN
19 I2C2.SCL 16 SCL
20 I2C2.SDA 20 SDA
25 mcasp0_ahclkx 17 MCLK
28 mcasp0_axr2 13 DIN
29 mcasp0_fsx 7 WCLK
30 mcasp0_axr0 11 DOUT
31 mcasp0_aclkx 3 BCLK
43 GND 18
7 1V8D VOUT

Regards,
John

Hi John,

Thanks for the detailed info.

I am actually trying to route to the mono line but having difficulties, have you attempted to do that? We have a custom board with an on-board TLV320AIC3106 but want to connect up the EVM to a stock BBB to isolate potential hardware issues (and we can’t easily access the mono line as it is connected directly to the microphone input of another component). Using alsamixer, we’ve turned on the mono line, upped the DAC mixing volume to max and turned on DAC L mixing. DAC L is set to output to the mixer (L1). I was able to get this to work using the Windows software using what look to be similar / identical settings.

Ultimately, we are trying to loopback USB microphone input on one of the digital channels through to the MONO line, while at the same time routing LINE1L to the LEFT channel. Hopefully this is possible. It’s an inherited board design so we’re hoping to avoid hardware changes.

One thing we’ve been struggling to understand is what the audio routing section does in the device tree overlay so any advice you can give on that would be appreciated.

Best Regards,
Evan

Hi John,

Thanks for the detailed info.

I am actually trying to route to the mono line but having difficulties, have you attempted to do that? We have a custom board with an on-board TLV320AIC3106 but want to connect up the EVM to a stock BBB to isolate potential hardware issues (and we can’t easily access the mono line as it is connected directly to the microphone input of another component). Using alsamixer, we’ve turned on the mono line, upped the DAC mixing volume to max and turned on DAC L mixing. DAC L is set to output to the mixer (L1). I was able to get this to work using the Windows software using what look to be similar / identical settings.

Ultimately, we are trying to loopback USB microphone input on one of the digital channels through to the MONO line, while at the same time routing LINE1L to the LEFT channel. Hopefully this is possible. It’s an inherited board design so we’re hoping to avoid hardware changes.

One thing we’ve been struggling to understand is what the audio routing section does in the device tree overlay so any advice you can give on that would be appreciated.

Look at /Documentation/devicetree/bindings/sound/tlv320aic3x.txt

I think you need MONO_LOUT connected to LINE1L

See also /Documentation/devicetree/bindings/sound/davinci-evm-audio.txt

Regards,
John