This worked for me when installing Mopidy on my Cubox-i with Arch Linux.
Follow the usual installation steps, or use pip to install mopidy. Install any additional plugins you might need with pip2, such as Mopidy-Spotify (if you are installing spotify you need libspotify).
Now do any required configuration.
Finally it is necessary to configure mopidy to use HDMI as output. In order for this to work the alsasink for gstreamer is needed, which is part of the gstreamer0.10-base-plugins package, and set ‘
output = alsasink‘ as described here. My /etc/asound.conf is setup as follows: