BBB Audio Cape RevB Getting Started

This guide is intended to walk through the basic instructions on how to get your Audio Cape working. If you have any question, please email [mailto:support@circuitco.com support@circuitco.com].

To purchase the Audio Cape please visit BoardZoo.com

To purchase the BeagleBone Black please visit BeagleBoard.org

The instructions below are performed under following kernel and may vary for different kernel versions.

Load the device tree file
Ensure your BBB is connected to the internet. Download the provided device tree file and decompress it. You may end up doing something like this: If you don't have unzip installed. Run as root: Compile the device tree file and move it to /lib/firmware: Since this Audio Cape uses the same audio signal from the onboard HDMI interface, you need to disable the audio portion of the HDMI by edit the uEnv.txt at /boot/uboot. Add this line to the uEnv.txt file:

Reboot your BBB. Log in and check the capemgr: Note that the "virtual cape" BB-BONELT-HDMIN is loaded instead of the BB-BONELT-HDMI. The difference between the two "capes" is that the BB-BONELT-HDMIN does not include the audio portion. Now load the DT file for Audio Cape: The Audio Cape is now loaded.

Play Audio Files
Before playing an audio file, you may need to set the volume and configuration of the codec. Download the asound.state file to /etc/var/alsa. You may need to reboot your BBB (and load the Audio Cape DT file again if required).

Play a WAVE file
To play a WAVE file (say sample.wav), run:

Record an audio input
To record an audio input, you can use a male-to-male audio cable to connect from an audio source (phone, lapotp, etc) to the audio input connector on the Audio Cape. Run the command below Play the recorded file: