bz31

# Delete prior revisions from a GitHub wiki so that only the most-recent
# version of the content is available.

# Clone the wiki.
git clone https://github.com/[user]/[repo].wiki.git
# Example: git clone https://github.com/bz31/Buildroot.wiki.git

# Remove the .git folder.
cd [repo].wiki
rm -rf .git

bz31

About

This gist will show how to setup Raspbian Stretch as a headless Bluetooth A2DP audio sink. This will allow your phone, laptop or other Bluetooth device to play audio wirelessly through a Rasperry Pi.

Motivation

A quick search will turn up a plethora of tutorials on setting up A2DP on the Raspberry Pi. However, I felt this gist was necessary because this solution is:

• Automatic & Headless - Once setup, the system is entirely automatic. No user iteration is required to pair, connect or start playback. Therefore the Raspberry Pi can be run headless.
• Simple - This solution has few dependencies, readily available packages and minimal configuration.
• Up to date - As of December 2017. Written for Raspbian Stretch & Bluez 5.43

Prerequisites

bz31

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

bz31

# Install mtd-utils

# $UBIFS is a ubifs image file
# make sure $UBIFS is a ubifs image file
blkid $(UBIFS)
  $(UBIFS): ... TYPE="ubifs"

# size of created mtd is 256.0 MiB
/usr/sbin/modprobe nandsim first_id_byte=0x2c second_id_byte=0xda third_id_byte=0x90 fourth_id_byte=0x95
/usr/sbin/flash_erase /dev/mtd0 0 0