Low-Latency Multichannel Audio System (2 x 24 Bit stereo inputs, 4 x 24 Bit stereo outputs)

audio, embedded, linux, alsa, asoc, multichannel, eurorack, diy, interface, i2s, tdm, pcm, am335x, ad1938, musictech, synthesizer, open source, DSP, ctag face 2|4

Low-Latency Multichannel Audio System (2 x 24 Bit stereo inputs, 4 x 24 Bit stereo outputs)

Posted by Pete W on 2016-02-15T23:03:30-05:00

Categories: BeagleBone Black


Multichannel audio system based on BeagleBone Green/Black and AD1938 audio codec by Analog Devices Inc. The audio system offers 2 x 24 Bit stereo ADCs and 4 x 24 Bit stereo DACs.


  • 2 stereo ADCs and 4 stereo DACs
  • Up to 96 kHz sampling rate with 8 audio channels (up to 192 kHz with 4 channels)
  • 24 Bit word width
  • Separate interfaces to ADCs and DACs
  • Asynchronous sampling rates for playback and capture
  • Up to 3,2 ms round-trip-time
  • Mobile usage (the Beaglebone Green and the audio card both are supplied with 5V supply voltage)

Project Components:

  • I2S sound card (CTAG face2|4)
  • Forked BeagleBone Linux kernel 4.1 with sound card drivers and modified device trees
  • Adapter card “bbg-cape” to connect the BeagleBone Black/Green with I2S sound card
  • Adapter card “con-cape” with stereo jacks and headphone amplifier, not yet published due to some bugs
  • BASH script for automatic evaluation of latency, THD+N, DNR, crosstalk and frequency response using GNU Octave
  • Surround-Delay audio effect for demonstration
  • Debian Wheezy SD card image for BeagleBone Green (evaluation script and demonstration effect is included)


  • Mobile sound studio (simultaneously record several inputs with different audio effects applied and preview them on different outputs in real time)
  • Programmable effect device for various music instruments
  • Open platform for DIY audio projects
  • Eurorack analog I/O interfaces

The complete project is open sourced.
For more details visit our website or our hackaday project.
Feedback is welcome:)

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