IMX8 Android Audio

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DART-MX8M - Android Oreo - Audio

Android Audio

To give you an overview we recommend you go through the https://source.android.com/devices/audio document(s).
and get familiar with the terminologies and configuration.
This requires prior knowledge of the Linux Kernel Alsa layer and https://www.alsa-project.org/wiki/Developer_Zone

Android Provides

  1. Audio HAL from NXP
  2. Variscite adds EVK hardware support such as codec, and DMIC support to the HAL
  3. Once you program the images, it comes with the required HAL support to verify the Audio input / Output Functionality of the Dev Kit

Hardware Setup

DART-MX8M

- Line IN: J21 - Audio Jack 3.5 mm
- Headphone Out: J22 - Audio Jack 3.5mm
- DMIC: On board (Default Audio In route)

Audio In

- Connect 3.5 mm jack to Audio In: Ref:https://www.amazon.ca/AmazonBasics-3-5mm-Stereo-Audio-Cable/dp/B00NO73MUQ
- One end to Audio Output of the source you wish to record, one end to Audio In Jack of the DART-MX8M see above

Audio Output

- Connect 3.5 mm headphone jack to headphone/speaker

Audio In test

- Run below commands on adb shell

# tinymix 'Headphone Volume' 35;tinymix  'Capture Input' ADC;tinymix 'DMIC Mux' DMIC2;

- Start Sound Record as per below screen shot
- If app asks for permissions click on allow for microphone and internal stroage dialoge
- Make sure you have audio line in source is playing some music
- Click on the record button and you should see below screen
Imx8 Audio In.png

Audio Out test

- To review recorded audio, you may click on the play button
Imx8 Audio Review.png
- Click on the music player app (Cactus Player)
Imx8 Audio Out Cactus Player.png
- Click on music / recorded audio you captured
Imx8 Audio Out Cactus Playing Audio.png