Audio-USB
===========

The phyCORE-i.MX7 development kit provides audio over USB2.0 (X9). This guide will demonstrate how to connect and use a USB headset for audio and microphone support.

Requirements
---------------

* Logitech H570e headset

* CAT5e cable (comes included with the development kit)

* Network switch connected to a DHCP enabled network

Hardware Setup
-------------------

* Plug the headset into the USB2.0 (X9) connector.

  .. image:: ../../images/phycore-imx7/pcm-061_audio-setup.webp
    :width: 500px

After the device is connected, you should see Linux console output similar to the below:

.. code-block:: none
  :caption: Expected Output

  root@phyboard-zeta-imx7d-1:~# usb 1-1: new full-speed USB device number 6 using ci_hdrc
  usb 1-1: Warning! Unlikely big volume range (=4125), cval->res is probably wrong.
  usb 1-1: [11] FU [Sidetone Playback Volume] ch = 1, val = 0/4125/1
  input: Logitech Inc Logitech H570e Stereo as /devices/soc0/soc/30800000.aips-bus/30b10000.usb/ci_hdrc.0/usb1/1-1/1-1:1.3/0003:046D:0A56.0005/input/input6
  hid-generic 0003:046D:0A56.0005: input: USB HID v1.11 Device [Logitech Inc Logictech H570e Stereo] on usb-ci_hdrc.0-1/input3

* Verify that the device was connected.

  .. code-block:: none
    :caption: Target (Linux)

    lsusb

  .. code-block:: none
    :caption: Expected Output

    root@phyboard-zeta-imx7d-1:~# lsusb
    Bus 001 Device 006: ID 046d:0a56 Logitech, Inc.
    Bus 001 Device 001: ID 1d6b:0002 Linux 5.15.71-bsp-yocto-nxp-i.mx7-pd23.1.0 ehci_hcd EHCI Host Controller

* Next, connect an Ethernet cable from X8 on the development kit carrier board to a network switch that is connected to a DHCP-enabled network.

Playing Audio
---------------

* Copy an audio file onto the develoment kit.

  This example will use the wget command, which requires a network connection. Discover more mediums that can assist in copying files by following the guide :ref:`cpyFiles-7`.

  .. code-block:: none
     :caption: Target (Linux)

     wget |intf-audio-wav-http-link|

* Play the audio file.

  .. code-block:: none
    :caption: Target (Linux)

    aplay ImperialMarch60.wav

  .. code-block:: none
    :caption: Expected Output

    root@phyboard-zeta-imx7d-1:~# aplay ImperialMarch60.wav
    Playing WAVE 'ImperialMarch60.wav' : Signed 16 bit Little Endian, Rate 22050 Hz, Mono

Recording Audio
-----------------

* Use 'arecord' to record audio using the microphone on the headset. The following command will record audio from the microphone for 10 seconds and save it to testrecord.wav.

  .. code-block:: none
    :caption: Target (Linux)

    arecord -d 10 -f cd -t wav testrecord.wav

* Use the following to play the file.

  .. code-block:: none
    :caption: Target (Linux)

    aplay testrecord.wav

Audio Mixer Settings
---------------------

* Control volume and various other audio setting using the ALSA soundcard driver's *'amixer'* or *'alsamixer'* commands.

  .. code-block:: none
    :caption: Target (Linux)

    alsamixer

A GUI interface will pop up. This can be navigated using arrow keys.

.. image:: ../../images/phycore-imx7/pcm-061_audio-mixer.webp
  :width: 500px

.. tip:: Click on the link for more information about alsamixer: https://linux.die.net/man/1/alsamixer