IOU06 Quick-Start-Guide / Audio Demo

Audio Support Demo

In this demo, we’ll show how to use the audio interface of the IOU06 extension module.

Hardware

  • A Moducop Edge Computer with a IOU06 installed
  • A development PC (Windows or Linux), connected via Network to the Moducop
  • A speaker

Play a WAV File

This chapter describes how to play a WAV file on the audio output interface of the IOU06 without the need of any specific configuration.

Connecting the Audio Interface to a Speaker

Audio Connection

Copy a WAV File to the Moducop

Connect a PC and Moducop to the same network, e.g. by using an Ethernet Switch or a Wifi Access Point and copy a WAV file to the Moducop:

scp /path/to/file.wav root@<moducop-ip>:~/file.wav

Playing the WAV File

Then login into the Moducop via ssh and use the aplay command to play it:

root@moducop-cpu01: ~# aplay -D hw:0,0 ~/file.wav

This command will play the file on the first subdevice of the first audio card (hw:0,0).

If you have connected more than one audio card to the Moducop, you can use the aplay -l command to list all available audio cards and subdevices:

root@moducop-cpu01-06895147:~# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: CODEC [USB AUDIO  CODEC], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Loop Back the Audio Output to the Audio Input

This chapter describes how to loop back the audio output to the audio input of the IOU06 without any specific configuration.

Connecting Loops to the Audio Interface

Audio Connection

Record the Audio Output

Copy a WAV file to the ModuCop as described in chapter Copy a WAV File to the Moducop.

Attention The WAV file must have only one channel (mono), because only one channel of the audio output interface is connected to the audio input interface.

Then login into the Moducop via ssh and use the arecord command to record the audio output:

root@moducop-cpu01: ~# arecord -D hw:0,0 -f S16_LE ~/record-file.wav

The arecord command will record the audio input of the first subdevice of the first audio card (hw:0,0) and save it to the file.wav file.

Info: S16_LE is the sample format of the audio data. You can use arecord --help to list all available sample formats.

In another terminal, play the WAV file:

root@moducop-cpu01: ~# aplay -D hw:0,0 ~/file.wav

Playing the Recorded Audio File

To play the recorded audio file, connect a speaker as described in chapter Connecting the Audio Interface to a Speaker and use the aplay command:

root@moducop-cpu01: ~# aplay -D hw:0,0 ~/record-file.wav