IMX8 Android Audio

From Variscite Wiki
Revision as of 23:55, 12 September 2023 by Harshesh (talk | contribs) (→‎DMIC test)
Warning: This page is designed to be used with a 'release' URL parameter.

This page is using the default release RELEASE_O8.1.0_1.3.0_8M_DART-MX8M.
To view this page for a specific Variscite SoM and software release, please follow these steps:

  1. Visit variwiki.com
  2. Select your SoM
  3. Select the software release
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

DMIC test

By default, if you don't connect the audio input is selected via onboard DMIC - Start Sound Recorder app as per below screen shot
- If app asks for permissions click on allow for microphone and internal stroage dialoge

Line In test

Use the above recording application to record via the application.

- Run below commands on adb shell

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

- Make sure you have an audio line in source playing some music if you are performing Line In test
- Click on the record button and you should see the 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