mopidy-gpiovolume

Mopidy volume control and standby control for a hacked Logitech Z-680 through GPIO

Hardware description can be found here:

https://hackaday.io/project/21792-logitech-z-680-music-streamer

Installation

I'll try to describe everything i've used to install and make this work, i'm working with Raspbian Jessie. I'm assuming you downloaded this repository in your pi home directory and are running from that directory.

Install the cpp service

Install the kernel headers (don't know if the headers is used where allready there, so maybe this can be skipped)

$ sudo apt-get install raspberrypi-kernel-headers

Install WiringPi (used to drive the GPIO)

$ sudo apt-get install wiringpi

Compile volume control program:

$ gcc -Wall -o gpiovolume mopidy-gpiovolume/gpiovolume.cpp -lwiringPi -lrt

Create a service file in /etc/systemd/system/gpiovolume.service

[Unit]
Description=Volume Control by GPIO
After=network.target

[Service]
Type=simple
User=root
WorkingDirectory=/
ExecStart=/home/pi/gpiovolume
Restart=on-abort

[Install]
WantedBy=multi-user.target

You might want to change the location for the process to be in /usr/sbin. I left it in the home so i can easily recompile it.

Start the service

$ sudo systemctl start gpiovolume.service

You can check if it is running with

ps -aux | grep gpiovolume

There should be a gpiovolume entry in /dev/shm this is the shared memory file that holds the volume and standby status. The cpp service is following those values.

Install the mopidy plug in

Install the Python dev tools (needed to install possix_ipc)

$ sudo apt-get install python-dev

Install posix_ipc

$ sudo pip install posix_ipc

Install gpiovolume

$ sudo pip install mopidy-gpiovolume

Edit the Mopidy configuration to use the volume mixer in /etc/mopidy/mopidy.conf

$ [audio]
mixer = gpiovolume
mixer_volume = 15

Restart mopidy and everything should be working