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.

To make the Beaglebone load the cape every time:

and add the following line

CAPE=BB-BONE-AUDI-02

Save and reboot and the DTBO for the cape will load each time it is booted.

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:

=Alsamixer controls that are active and work= alsamixer provides controls for *most* of the chip. There are, however, only somethat matter and work. for recording and playback.

Playback
PCM - Sets the level of playback from recorded audio.

Line - When this is Green with QQ in the display the LIne Mixer is enabled. Line DAC - Sets Global Line output level Left Line Mixer DACL1 - When this is Green and has QQ displayed Left Line Output is enabled Left Line Mixer DACR1 - Sets Left Line output level (leave up full) Right Line Mixer DACL1 - When this is Green and has QQ displayed Right Line Output is enabled Right Line Mixer DACR1 - Sets Right Line output level (leave up full)

HP - When this is Green with QQ in the display the Headphone output is enabled. HP DAC - Global Headphone output level. (use this to set level of Headphones) Left HP Mixer DACL1 - When this is Green and has QQ displayed Left Headphone is enabled Left HP Mixer DACR1 - Sets Left Headphone output level (leave up full) Right HP Mixer DACL1 - When this is Green and has QQ displayed Right Headphone Output is enabled Right HP Mixer DACR1 - Sets Right Headphone output level (leave up full)

Left PGA Mixer Mic3L - When Green and has QQ displayed MIc3L is enabled (This is the Input setting for this Cape) Right PGA Mixer Mic3R - When Green and has QQ displayed MIc3R is enabled (This is the Input setting for this Cape)

Falsely in playback-view: ADC HPF Cut-off - Enable / disable a (digital) high pass filter for capture (e.g. to remove DC offset)

Capture
PGA - Set Capture level (stereo or Mono) (This is the only control that works on Capture.)