I have been attempting to implement a sound record / playback application on a Rev C BeagleBone Black using the latest BBBAndroid image.
I have run into a brick wall. I am a self-confessed Android newbie, so any ideas/pointers from 'ye experts would be much appreciated.
To date, I have:
- Verified that the hardware is good by taking Android out of the equation.
(I verified audio playback/record to/from a USB headset, using the Gnome media sound recorder on the latest BeagleBoard Debian installation). - Verified that BBBAndroid recognizes the USB device (I see it in the log; also I have found that when I click on the headset’s volume control, the Android’s volume slider is displayed)
- Written a couple of USBAudio demo applications that can record and playback an mp4, or wav file.
(These have been failures - I have tried different implementations using the MediaPlayer, MediaRecorder and AudioRecord classes … read on).
What I have found:
a) The audio playback app generates no sound, either to the HDMI monitor, or a USB headset.
(actually, the BBB is completely mute, no notification sounds, no sound playback … it is quiet as a mouse).
b) The sound recorder app does create a wav, or mp4 file, but the file just contains rubbish.
I think that there could be something mis-configured in the Android build, but I can’t put my finger on it. For grins, I did set up the build environment and tried setting BOARD_USES_GENERIC_AUDIO to true in the BoardConfig.mk file, but it made no difference … of course 
Has anyone managed to get USB Audio to work on BBBAndroid?
Thanks in advance,
Graham