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
- 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
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;
- 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
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
