Device Setup

Configuring audio and MIDI devices for mtrack

Device Setup

mtrack requires class compliant audio and optionally MIDI devices. This guide covers discovering and configuring your devices.

Discovering Devices

Audio Devices

To see what audio devices mtrack recognizes:

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mtrack devices

Example output:

Devices:
- UltraLite-mk5 (Channels=22) (Alsa)
- bcm2835 Headphones (Channels=8) (Alsa)

The name before the parentheses is the identifier you’ll use in your configuration. In this example, you would use UltraLite-mk5 or bcm2835 Headphones.

MIDI Devices

To see what MIDI devices mtrack recognizes:

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mtrack midi-devices

Example output:

Devices:
- Midi Through:Midi Through Port-0 14:0 (Input/Output)
- UltraLite-mk5:UltraLite-mk5 MIDI 1 28:0 (Input/Output)

The name before the first colon is the identifier you’ll use in your configuration. In this example, you would use Midi Through or UltraLite-mk5.

Configuring Devices

Audio Device Configuration

In your mtrack.yaml configuration file:

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audio:
  device: UltraLite-mk5  # Use the device name from 'mtrack devices'
  sample_rate: 44100
  sample_format: int
  bits_per_sample: 32
  buffer_size: 1024
  buffer_threshold: 256
  playback_delay: 500ms

MIDI Device Configuration

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midi:
  device: UltraLite-mk5  # Use the device name from 'mtrack midi-devices'
  playback_delay: 500ms

Tested Devices

Audio Cards

mtrack has been tested with:

  • MOTU UltraLite-mk5 - 22 channels
  • Behringer X32 (through X-Live card)
  • Behringer Wing Rack
  • Raspberry Pi onboard audio (bcm2835)

MIDI Interfaces

Tested MIDI devices include:

  • MOTU UltraLite-mk5 - Built-in MIDI interface
  • Roland UM-ONE - USB MIDI interface
  • CME U6MIDI Pro - USB MIDI interface

DMX Interfaces

DMX is supported through OLA (Open Lighting Architecture). Tested devices:

  • Entec DMX USB Pro
  • RatPac Satellite (Art-Net and sACN)

Troubleshooting

Device Not Found

If your device doesn’t appear in the device list:

  1. Check device connection: Ensure the device is connected and powered on

  2. Check permissions: You may need to add your user to the audio group:

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    sudo usermod -a -G audio $USER

    Then log out and back in.

  3. Check ALSA: For audio devices, check if ALSA recognizes them:

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    aplay -l

  4. Check udev rules: Some devices may need udev rules for proper access

Permission Errors

If you get permission errors:

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# Add user to audio group
sudo usermod -a -G audio $USER

# For MIDI devices, you may need:
sudo usermod -a -G dialout $USER

Then log out and log back in for changes to take effect.

Device Name Matching

mtrack uses partial matching for device names. If you have multiple similar devices, use a more specific portion of the name, or the full name if needed.