matt on 20 Mar, 2017 09:28 PM
I'm not sure if you can get it to work via the sound card. The two standard methods are reading from a TNC over a serial port, and reading from the APRS-IS network. Note that I haven't officially documented these in the knowledge base yet since an upcoming item is to remove 'sarsoft' prefixes from the properties file entries, so the exact property names may change soon.
For serial ports, you should just need to set sarsoft.location.aprs.local.enabled=true in the properties file, and any connected serial ports will be connected to automatically.
For APRS-IS, set sarsoft.location.aprs.is.enable=true. You should set sarsoft.location.aprs.is.user= to your ham callsign; this isn't necessary as aprs-is allows anonymous access but would let someone contact you if your connection was misbehaving. You can also set sarsoft.location.aprs.is.serverName and .serverPort if you want to use a different APRS-IS server, or roll your own based on locally received data, but at the moment the filter is fixed to "a/50/-125/25/-66 -t/oimqstunw" with no way to customize it.