IMX8 Android Audio
1 Android Audio
To give you overview we recommend you go through the https://source.android.com/devices/audio documents.
1.1 Android Provides
- Audio HAL from NXP
- Variscite adds EVK hardware support such as codec, DMIC support to the HAL.
- Once you program the images, it comes with the required HAL support to verify the Audio input / Output Functionality.
1.2 Hardware Setup
- Line IN: J21 - Audio Jack 3.5 mm
- Headphone Out: J22 - Audio Jack 3.5mm
- DMIC: On board
1.2.2 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
1.2.3 Audio Output
- Connect 3.5 mm headphone jack to headphone / speaker
2 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
3 Audio Out test
4 DMIC test
By default if you don't connect the audio input is selcted via on board DMIC
Use above recording application to record via the application.