First of all: This project is a clone of CircuitCo Audio Cape.
It is not commercial in any form, just fun for me to play around. If you want an Audio Cape, go and get one of theirs.
Project schematic.
Render of the board.
The setup guide is mainly taken from eLinux.org - BBB Audio Cape RevB Getting Started.
Get the tools if not already installed:
pacman -S wget
pacman -S unzip
pacman -S dct-overlay
Download and unzip the device tree source:
wget http://elinux.org/images/1/10/BB-BONE-AUDI-02-00A0.zip
unzip BB-BONE-AUDI-02-00A0.zip
Compile the device tree file and move it to /lib/firmware:
dtc -O dtb -o BB-BONE-AUDI-02-00A0.dtbo -b 0 -@ BB-BONE-AUDI-02-00A0.dts
mv BB-BONE-AUDI-02-00A0.dtbo /lib/firmware
Notice that the dtc-overlay version needs to be installed, since the old dtc is not accepting the @ option.
The Cape is sharing the audio signal with the onboard HDMI. Therefore HDMI audio needs to be disabled. Edit the uEnv.txt file, that your uboot is using:
optargs=capemgr.disable_partno=BB-BONELT-HDMI
In order to activate the cape you need to reboot. Load the Device Tree file for the cape:
echo BB-BONE-AUDI-02 > /sys/devices/bone_capemgr*/slots
To make that persistent just add the following line in /etc/default/capemgr :
CAPE=BB-BONE-AUDI-02
Play alternating noise on the 2 output channels:
speaker-test -c 2
Play alternating sine waves on the 2 output channels:
speaker-test -c 2 -t sine
| Identifier | Type/Value | Quantity | Comment | Supplier Id | Supplier |
|---|---|---|---|---|---|
| R1, R2 | 0 Ω | 2 | not populated | SMD-0603 0 | Reichelt |
| R5, R6 | 33 Ω | 2 | SMD-0603 33 | Reichelt | |
| C3, C4, C20, C21 | 47 pF | 2 | NPO-G0603 47P | Reichelt | |
| C13 | 10 nF | 1 | X7R-G0603 10N | Reichelt | |
| C1, C2, C5, C6, C15, C16 | 100 nF | 6 | X7R-G0603 100N | Reichelt | |
| C7-C10, C14, C17 | 10 µF | 6 | X5R-G0603 10/6 | Reichelt | |
| C18, C19 | 47 µF | 2 | X5R-G1206 47/6 | Reichelt | |
| J1, J2 | 4pol TRS Jack | 2 | LUM 1503-13V | Reichelt | |
| J3, J4 | 2row Pin Header | 2 | SL 2X25G 2,54 | Reichelt | |
| D1-D4 | Suppressor Diodes | 4 | 863-ESD9B3.3ST5G | Mouser | |
| U1 | Stereo CODEC | 1 | 595-TLV320C3104IRHBT | Mouser | |
| U2 | LDO 1.8V | 1 | 595-TLV70218DBVR | Mouser |