6.2.2 ALSA Testing Procedure

  1. Ensure the TOSLINK optical cable is connected at one end to SAMA7G54-EK SPDIF TX and at the other end to SPDIF-In on the USB audio extender, as explained in Hardware Setup.
  2. To check the SPDIF TX audio device card number and device number, use the following command:

    $ aplay -l | grep spdiftx

    In the capture below, the card number is 0 and the device is 6.

  3. To test the SPDIF TX using the speaker-test command:

    $ speaker-test -Dplughw:0,6 -c 2 -t wave

    Listen to the audio data, making sure it can be heard on the Front left and Front Right audio channels.

  4. Play the .wav file transmitted through the SPDIF TX interface using the following command:

    $ aplay -Dplughw:0,6 -r 48000 -c 2 -f S16_LE pdmc.wav

    In this capture, pdmc.wav is an input audio file.