Genio 350-EVK

Overview

On i350-EVK, there are 3 playback hardware and 3 capture hardware.

  • Playback

    • Line-Out Jack

    • Headset-Out Jack

    • HDMI Audio Out

  • Capture

    • Headset-In Jack

    • AMIC In

    • DMIC In

One line-out jack is used for the external amplifier. One headset jack can be connected to the earphone which has both playback and capture functions. AMIC is a mono analog microphone on the board. DMIC is a stereo digital microphone on the board.

../../../../_images/sw_rity_app-dev_audio_hardware.png

Audio hardware position

The default routing is shown below. There are 2 playback nodes and 2 capture nodes.

../../../../_images/sw_rity_app-dev_audio_route.png

The route between hardware and device node

  • pcmC0D0p plays the sound to either Line-Out Jack or Headset-Out Jack.

  • pcmC0D1p plays the sound to HDMI Audio Out.

  • pcmC0D2c records the voice from either Headset-In Jack or AMIC.

  • pcmC0D3c records the voice from 2-ch DMIC.

Playback

Headset Jack Speaker

By default, the i350-EVK board plays the audio to the first jack connector (headset) and the second jack (line-out) is disabled. To play the music through the jack, you can use either gst-play-1.0 or aplay.

gst-play-1.0 is a tool used to test basic playback using the GStreamer element playbin. For more details about gst-play-1.0, please refer to gst-play-1.0.

gst-play-1.0 sample.mp3

aplay is a command-line sound file player for the ALSA sound card driver. For more details about aplay, please refer to aplay.

aplay -D jack_speaker sample.wav

It is possible to switch to the second line. To do that, you will need to change some ALSA settings by using the following commands:

  • To disable the headset-out jack and enable the line-out jack:

    amixer cset -c mtsndcard name='Audio_Amp_L_Switch' 0
amixer cset -c mtsndcard name='Audio_Amp_R_Switch' 0
amixer cset -c mtsndcard name='Speaker_Amp_Switch' 1

  • To switch back to the headset-out jack:

    amixer cset -c mtsndcard name='Audio_Amp_L_Switch' 1
amixer cset -c mtsndcard name='Audio_Amp_R_Switch' 1
amixer cset -c mtsndcard name='Speaker_Amp_Switch' 0

There are gain controls for the audio outputs. You can use these controls to adjust the volume:

  • To control the gain of the headset-out jack:

    # Max volume
amixer cset -c mtsndcard name='Headset_PGAL_GAIN' 0
numid=131,iface=MIXER,name='Headset_PGAL_GAIN'
  ; type=ENUMERATED,access=rw------,values=1,items=32
  ; Item #0 '8Db'
  ; Item #1 '7Db'
  ...
  ; Item #30 '-22Db'
  ; Item #31 '-40Db'
  : values=0

    # Min volume
amixer cset -c mtsndcard name='Headset_PGAL_GAIN' 31
numid=131,iface=MIXER,name='Headset_PGAL_GAIN'
  ; type=ENUMERATED,access=rw------,values=1,items=32
  ; Item #0 '8Db'
  ; Item #1 '7Db'
  ...
  ; Item #30 '-22Db'
  ; Item #31 '-40Db'
  : values=31

  • To control the gain of the line-out jack:

    amixer cset -c mtsndcard name='Lineout_PGAL_GAIN' 0
numid=135,iface=MIXER,name='Lineout_PGAL_GAIN'
  ; type=ENUMERATED,access=rw------,values=1,items=20
  ; Item #0 '8Db'
  ; Item #1 '7Db'
  ...
  ; Item #18 '-10Db'
  ; Item #19 '-40Db'
  : values=0

    amixer cset -c mtsndcard name='Lineout_PGAL_GAIN' 19
numid=135,iface=MIXER,name='Lineout_PGAL_GAIN'
  ; type=ENUMERATED,access=rw------,values=1,items=20
  ; Item #0 '8Db'
  ; Item #1 '7Db'
  ...
  ; Item #18 '-10Db'
  ; Item #19 '-40Db'
  : values=19

HDMI Speaker

To play the audio through HDMI, use the following command:

aplay -D hdmi_out sample.wav

Capture

Headset Jack Microphone

By default, the i350-EVK board records the voice from the headset jack microphone. The following command is an example that will start a mono record with 48KHz sampling rate and signed 32bits bit format:

arecord -D jack_mic -r 48000 -f S32_LE sample.wav

Digital Microphone

You can record the voice from the 2 PDM mics on the board. In this case, the device will need to be specified explicitly as follows:

arecord -D dmic -r 48000 -f S32_LE -c 2 sample.wav

Analog Microphone

You can record the voice from the analog mic on the board. In that case, you will need to switch from the jack mic to the analog mic by using the following command:

# Switch microphone to AMIC
amixer cset -c mtsndcard name='Audio_MicSource1_Setting' 0
numid=161,iface=MIXER,name='Audio_MicSource1_Setting'
  ; type=ENUMERATED,access=rw------,values=1,items=4
  ; Item #0 'ADC1'
  ; Item #1 'ADC2'
  ; Item #2 'ADC3'
  ; Item #3 'ADC4'
  : values=0
arecord -D jack_mic -r 48000 -f S32_LE sample.wav

To switch back to the jack mic, use the following command:

# Switch microphone to headset-in jack
amixer cset -c mtsndcard name='Audio_MicSource1_Setting' 1
numid=161,iface=MIXER,name='Audio_MicSource1_Setting'
  ; type=ENUMERATED,access=rw------,values=1,items=4
  ; Item #0 'ADC1'
  ; Item #1 'ADC2'
  ; Item #2 'ADC3'
  ; Item #3 'ADC4'
  : values=1
arecord -D jack_mic -r 48000 -f S32_LE sample.wav

Loopback Test

There’s a loopback audio test that directly transfers the input voice to the output audio. For example:

To transfer DMIC to headset-out jack:

# Enable headset-out jack and disable line-out jack
amixer cset -c mtsndcard name='Audio_Amp_L_Switch' 1
amixer cset -c mtsndcard name='Audio_Amp_R_Switch' 1
amixer cset -c mtsndcard name='Speaker_Amp_Switch' 0
# Transfer DMIC to headset-out jack
arecord -D dmic -r 48000 -f S32_LE -c 2 | aplay -D jack_speaker -r 48000 -f S32_LE -c 2

To transfer AMIC to line-out jack:

# Enable line-out jack and disable headset-out jack
amixer cset -c mtsndcard name='Audio_Amp_L_Switch' 0
amixer cset -c mtsndcard name='Audio_Amp_R_Switch' 0
amixer cset -c mtsndcard name='Speaker_Amp_Switch' 1
# Select AMIC
amixer cset -c mtsndcard name='Audio_MicSource1_Setting' 0
# Transfer AMIC to line-out jack
arecord -D jack_mic -r 48000 -f S32_LE | aplay -D jack_speaker -r 48000 -f S32_LE

To transfer headset-in jack to headset-out jack:

# Enable headset-out jack and disable line-out jack
amixer cset -c mtsndcard name='Audio_Amp_L_Switch' 1
amixer cset -c mtsndcard name='Audio_Amp_R_Switch' 1
amixer cset -c mtsndcard name='Speaker_Amp_Switch' 0
# Select headset-in jack
amixer cset -c mtsndcard name='Audio_MicSource1_Setting' 1
# Transfer headset-in jack to headset-out jack
arecord -D jack_mic -r 48000 -f S32_LE | aplay -D jack_speaker -r 48000 -f S32_LE

To transfer headset-in jack to HDMI audio out:

# Enable headset-out jack and disable line-out jack
amixer cset -c mtsndcard name='Audio_Amp_L_Switch' 1
amixer cset -c mtsndcard name='Audio_Amp_R_Switch' 1
amixer cset -c mtsndcard name='Speaker_Amp_Switch' 0
# Select headset-in jack
amixer cset -c mtsndcard name='Audio_MicSource1_Setting' 1
# Transfer headset-in jack to headset-out jack
arecord -D jack_mic -r 48000 -f S32_LE | aplay -D hdmi_out -r 48000 -f S32_LE