Strobe Receiver

http://strobe.audio

This is the Elixir umbrella app for the receiver side of the Strobe multi-room audio system.

This repo holds both the receiver Elixir application and also the Nerves based firmware application that allows the receiver to be installed as firmware on a Raspberry Pi 2/3 device.

Supported hardware

Currently the supported hardware is:

• Raspberry Pi 2
• Raspberry Pi 3
• IQaudIO Pi-DAC+
• IQaudIO Pi-DACZero

Beyond that you'll need to install & run a single Strobe Hub and to connect your chosen DAC(s) to an amplifier & speakers.

Burning the firmware

Download the image file latest release that matches your hardware then follow the instructions for writing to an SD card on the Raspberry Pi site.

Pop your new SD card into the RPi and you're good to go.

Running locally

It's possible to run the receiver locally if you'd like to play music through your computer or are interested in working on the Strobe system.

The receiver app is called janis.

Requirements

Erlang/OTP r18+

Mac:

brew install erlang

A working Elixir installation.

Currently only Elixir 1.3 is supported so the recommended approach is to install & use the asdf version manager.

First install asdf by following the instructions in the repo, then add the Elixir plugin and install Elixir 1.3.4

asdf plugin-add elixir https://github.com/asdf-vm/asdf-elixir.git
asdf install elixir 1.3.4
asdf local elixir 1.3.4

Libraries

Interfacing with your system's audio hardware is done via Portaudio which you can install via homebrew on a mac:

 brew install portaudio

or via apt on a Debian/Ubuntu machine:

 sudo apt-get install -y portaudio19-dev

Constant synchronisation of the audio is achieved by constant tiny amounts of audio resampling, this is done using libsamplerate

Mac:

 brew install libsamplerate

Debian/Ubuntu:

 sudo apt-get install -y libsamplerate0 libsamplerate0-dev

Service discovery is attempted using DNSSD/mDNS using Bonjour/Avahi:

 sudo apt-get install -y avahi-daemon libavahi-compat-libdnssd-dev

Building the Firmware

The following will build the Strobe Receiver firmware and allow you to burn it to an SD card ready for booting your Receiver.

Requirements

You must run the following commands within a Linux environment, either real or virtualized.

First we need the buildroot dependencies:

sudo apt-get install git g++ libssl-dev libncurses5-dev bc m4 make unzip cmake

then you'll need a working Elixir 1.3 installation as detailed above.

Building

The following instructions will build firmware for a Raspberry Pi 3. If you want to build for a Raspberry Pi 2, then replace rpi3 with rpi2 in all the subsequent commands.

This requires a lot of diskspace, so make sure you have something like 8GB of freespace on whichever disk you're doing this on.

I'm assuming a subdirectory of your home partition here, but you can do this from anywhere, you just need to reference the location in the subsequent mix commands.

The following commands will generate & compile the required buildroot environment for the Strobe receiver firmware.

mkdir ~/nerves-firmware
cd ~/nerves-firmware

git clone https://github.com/nerves-project/nerves_system_br.git
git clone https://github.com/strobe-audio/nerves_system_rpi3

mkdir NERVES_SYSTEM_RPI3
cd nerves_system_br

./create-build.sh ../nerves_system_rpi3/nerves_defconfig ../NERVES_SYSTEM_RPI3

cd ../NERVES_SYSTEM_RPI3
make

This will take a long time the first time it is run -- subsequent builds are incremental & will be quicker.

Once that's complete we are ready to build & burn the Elixir side of things.

If you haven't already done so, clone this repository

cd ~

git clone https://github.com/strobe-audio/strobe-receiver.git

cd strobe-receiver/apps/nerves_janis

Be sure to reference the buildroot system you compiled in the previous steps.

NERVES_SYSTEM=~/nerves-firmware/NERVES_SYSTEM_RPI3 NERVES_TARGET=rpi3 mix deps.get

if you want you could make the NERVES_SYSTEM and NERVES_TARGET env settings persistent (I haven't done this so all the commands work out of the box).

export NERVES_SYSTEM=~/nerves-firmware/NERVES_SYSTEM_RPI3
export NERVES_TARGET=rpi3

Now we can compile the firmware into a .fw file ready for writing to our SD card using fwup

NERVES_SYSTEM=~/nerves-firmware/NERVES_SYSTEM_RPI3 NERVES_TARGET=rpi3 mix firmware

Now insert an SD card, if you haven't already:

NERVES_SYSTEM=~/nerves-firmware/NERVES_SYSTEM_RPI3 NERVES_TARGET=rpi3 mix firmware.burn

You're now good to go. Pop the SD card into your RPi3 and turn it on. You should see a new receiver appear in the Strobe UI.

License

Stobe Audio Receiver Copyright (C) 2017 Garry Hill

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.