IMX8 Android Audio
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:
- Visit variwiki.com
- Select your SoM
- Select the software release
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
- Audio HAL from NXP and json configuration files.
- Variscite adds EVK hardware support such as codec, and DMIC support to the HAL.
- 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
Audio Out test
- To review recorded audio, you may click on the play button
- Click on the music player app (Cactus Player)
- Click on music / recorded audio you captured
