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Audio

Overview⚓︎

Many of our platforms feature audio output and microphone input at the operating system level and, in some cases, via the on-board modem. To see if modem audio is supported, please consult the platform-specific modem pages.

On the Linux side we use standard ALSA.

T30 FR and T30⚓︎

This product comes with one 3.5 stereo phone jack with analog stereo audio out and one 3.5 stereo phone jack with mono in (microphone) interface. See technical specification for more information regarding the connectors.

CT and CT GL⚓︎

This product comes with a JAE IL-AG5-14P-D3L2 with analog stereo audio out and with mono in (microphone) interface. See technical specification for more information regarding the connectors.

MX-V⚓︎

This product comes with a 2x34PIN MINI50 2-BAY 90DEG PIN HEADER with analog stereo audio out and a mono in (microphone) interface. It's also possible to use HDMI audio from the DVI connector. See the technical specification for more information regarding the connectors.

C61⚓︎

This product comes with one 2.5 stereo phone jack with analog stereo audio out and with mono in (microphone) interface. See the technical specification for more information regarding the connectors.

Note: This feature is currently untested for modern BSPs.

Examples⚓︎

  • Example on how to create a loop back (activate mic and hear yourself) 

    arecord -d 5 -D plughw:1 -f dat output.wav & sleep 1 && aplay -D plughw:1 output.wav & echo recording and audio output

  • Test audio with a sinus tone at 997Hz. 

    speaker-test -D plughw:1 -t sine -r 997 -c 1 -l 2

speaker-test -D plughw:1,0 -t sine -r 997 -c 1 -l 2

  • list devices with aplay -L or aplay --list-devices (example from MX-V) 

    card 0: imxhdmisoc [imx-hdmi-soc], device 0: i.MX HDMI Audio Tx i2s-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Audiotlv320aic3 [Audio-tlv320aic310x], device 0: 2028000.ssi-tlv320aic3x-hifi tlv320aic3x-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0

For Linux 3.1 system⚓︎

Note: for BSP release 1.6/1.5 and older

To direct line-in to line-out:

amixer -c 2 set 'Left HP Mixer Line Bypass' on
amixer -c 2 set 'Right HP Mixer Line Bypass' on

Playback HDMI:

aplay -D 'default:CARD=tegra' bach.au

Playback:

amixer -c 2 set 'Headphone' 8 on
amixer -c 2 set 'Left HP Mixer PCM' on
amixer -c 2 set 'Right HP Mixer PCM' on
aplay -D 'default:CARD=T20' output2.wav

Record from line-in:

amixer -c 2 set 'Left Capture Select' 'Line'
amixer -c 2 set 'Right Capture Select' 'Line'
amixer -c 2 set 'Capture ADC' on
arecord -D 'default:CARD=T20' -v -f cd output2.wav

Record from mic:

amixer -c 2 set 'Left Capture Select' 'Mic'
amixer -c 2 set 'Right Capture Select' 'Mic'
amixer -c 2 set 'Capture ADC' on
amixer -c 2 set 'Left HP Mixer Mic Sidetone' on
amixer -c 2 set 'Right HP Mixer Mic Sidetone' on
arecord -D 'default:CARD=T20' -v -f cd output2.wav

Please note that the two numbers at the end specify which ALSA card and device to use for audio (e.g. alsasink device=hw:1,0 for SPDIF through HDMI and alsasink device=hw:2,0 for WM9715L AC97 through headphone).

aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
default:CARD=tegra // HDMI
    tegra,
    Default Audio Device
default:CARD=T20 // AC97
    Toradex Colibri T20,
    Default Audio Device