Appendix F Enabling Audio Components
The audio control driver (intel_qrk_audio_ctrl) provides a user-space interface via
sysfs to allow selecting one of the supported audio switch configurations to
interconnect the interfaces.
1. Load the following drivers to enable the audio components:
modprobe intel_qrk_audio_ctrl
modprobe snd-usb-audio
modprobe snd-usbmidi-lib
2. Test the audio hardware. Use the following command:
aplay -l
The sound card displays the following:
**** List of PLAYBACK Hardware Devices ****
card 0: CODEC [USB audio CODEC], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
The audio subsystem has three interfaces that can be interconnected in a fixed set
of configurations:
•
USB soundcard interface, connected to the CPU
•
External speaker/microphone jacks
•
Maxim* Integrated 9867 I2S codec that interfaces with a Telit* HE910 GSM
modem
3. Select one of the following supported audio switch configurations to interconnect
the interfaces:
•
Interconnect the audio interfaces:
echo gsm > /sys/bus/i2c/devices/0-0018/audio_switch_mode
•
Set an audio path between the CPU and GSM:
echo spkr > /sys/bus/i2c/devices/0-0018/audio_switch_mode
•
Set a unidirectional audio path between the CPU and external speaker output
port. This option is suitable for playback of a wav file or another audio format
to external speakers, such as vehicle speakers:
echo spkr_mic > /sys/bus/i2c/devices/0-0018/audio_switch_mode
Intel IoT Gateway Development Kit DK200 Series —Enabling Audio Components
Intel
®
IoT Gateway Development Kit DK200 Series
Getting Started Guide
April 2015
72
Order No.: 330295-004
