Mopidy-dam1021

Mopidy extension for controlling volume using a dam1021 DAC device.

Installation

Install by running:

sudo pip install Mopidy-dam1021

Configuration

The Mopidy-dam1021 extension is enabled by default. To disable it, add the following to mopidy.conf:

[dam1021]
enabled = false

The dam1021 DAC must be connected to a serial port of the machine running Mopidy. This does not meant the both devices must be physically connected together using a serial cable. Although this is the most obvious configuration. Another option is to use network tunneling using socat or any other similar utility. Bear in mind system user on behalf of which Mopidy operates on must have proper access rights to a serial port. E.g. the following needs to be done on Raspian:

# usermod -G dialout mopidy

To use the DAC to control volume, set the audio/mixer config value in mopidy.conf to dam1021mixer. You probably should add some properties to the dam1021 config section too.

The following properties are available:

• serial: The serial device to use, defaults to /dev/ttyAMA0. This must be set correctly for the mixer to work.
• volume_inf: The DAC volume control utilizes idea of signal attenuation in a digital domain, where 0 means unaltered signal, -80 - maximal attenuation, 10 - maximal gain. This property defines lower bound of volume levels available to the mixer. Usually you should operate between -80 and 0. Using narrower margins translates to a finer volume control. Defaults to -80.
• volume_sup: The upper bound of volume levels available to the mixer. See volume_inf. Defaults to 0.
• timeout: Timeout value for any given operation on serial line, used by a lower level library. Expressed in milliseconds. Defaults to 2000.

Configuration example with all default values, suitable for Raspberry Pi users:

[audio]
mixer = dam1021mixer

Configuration example, if the DAC is available elsewhere:

[audio]
mixer = dam1021mixer

[dam1021]
port = /dev/ttyUSB0

Configuration example with a customized volume level range:

[audio]
mixer = dam1021mixer

[dam1021]
port = /dev/ttyUSB0
volume_inf = -45
volume_sup = -5

Bugs

Please use issue tracker for reporting.

Additional resources

• Source code
• Dam1021 communication library
• Official DAC page