BeagleBone Black Wireless and I2S audio output

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1

Hello everyone,

I need your help.

I have a BeagleBone Black Wireless, on which I installed the standard Jessie Debian distribution.
I want to add an audio output with the I2S, and i wish to keep HDMI working.

I also have a DAC (Phat DAC) which is originally made for the Raspberry pi zero.

I’m aware that the HDMI chip is receiving the I2S data that is generated by the processor. (see this article for details)

I have use the BBBW shematics and the Ohat DAC pinout (did not find the schematics) to connect the 2 boards.

connections:

  • GND (phat pin 6, 39 <-> BBB P9_1 )
  • 5V (phat pin 2 & 4 <-> BBB P9_5 & P9_6)
  • 3.3V (phat pin 1 <-> BBB P9_3)
  • I2S LRCLOCK (phat pin 12 <-> BBB P9_28)
  • I2S SCLK / bitclock (phat pin 35 <-> BBB P9_31)
  • I2S data (phat pin 40 <-> BBB P9_29)

To test my speaker output i run
$ speaker-test -F S32_LE -f 48000 -c 2

I have no sound (i also tried with aplay to read WAV files and mplayer just in case)

Does anyone has any idea if:

  • my connections are bad
  • if i must connect the HDMI screen to get the audio output on the I2S bus (because of OS settings) i tried with and without the screen without success
  • if i have to change the drivers (I’ve read about the botic driver but the HDMI should send audio on I2S)

ALso in the future i expect to use GPIO3_21 to add a Master clock (as apparently the BBBW is limited to 48kHz sample rate family)

Thank you in advance for any help

Best

2

Hi adrien,

I also wanted to play I2S output audio on BBB. I have 2 DACs ,one based on PCM5101A,other based on TLV320AIC23 CODEC. But the device tree overlays are handled differently in newer Debian images. which is the DAC which you used and can you please guide how to add the audio cape to the device tree and make it working? I am not an expert in linux. any help will be very useful.
Thanks in advance.
Jithu

3

Please help me for the same problem.
I need to play Audio via i2s in beaglebone board.

Thanks