Thursday, April 23, 2009

More D-Star development.., & thoughts


I wasn't going to write another D-star related blog this month. But Chris' feedback and some news that Scott, KI4LKF released some source code of his work changed that.

The rtpdir bridge - to bridge EchoLink, IRLP, D-Star and Asterisk.

I'm very glad to see him release his source code despite some some of the childish antics that some other developers are playing. Scott has written a number of handy bridging utilities. His raw2ambe utility fits nice with some of my other thinking that I'll be diving into in a second. This utility is for converting MP3-format or WAV-format audio files to RAW audio data files that can be fed to the dongle which
eventually will create D-STAR AMBE-codec data files which can be announced on a D-STAR repeater.

The ID-RPC2 D-Star repeater controller basically just regenerates and routes data between RF modules.

It doesn't have an Analog to Digital Converter, the AMBE2020. Therefore it's a no frills controller. You won't be able to program it to announce club meetings or any kind of salutations.

However if you add a DV dongle to provide this conversion to AMBE, of course this is all possible with some scripting. As a matter of fact since each user transmission contains a callsign, you should be able to create custom greetings based off decoded data, by using a text to speech engine such as Cepstral or Festival. "Welcome KB9MWR to the K9EAM D-Star repeater." "You have one voice mail message from N9PAV, left yesterday"... A relational database or QRZ lookup could even make it more personal with first name greetings. Last heard callsign stats could be kept and queried via touch tones and/or exported to a club webpage. Short air temperature and wind speed reports could be sent out periodically as a a short text message to users radios.

Scott, KI4LKF just released a new tool released for making TEXT announcements on D-STAR repeaters. dextra_send_text is similar to dextra_send, except dextra_send is for D-STAR audio announcements. While dextra_send_text is for TEXT announcements. The text is the usual 20-character message that will go to all D-STAR radio displays of all D-STAR radio users listening on a specific D-STAR repeater module.


Really there is so much that can be done here.... This is what interests me about D-Star, as the experimental/technical side of ham radio has always appealed to me more than the operational side. Most of this prgamming is a bit beyond myself and others as it involves on the fly parsing from live IP streams, as well as packet injection. But as you can see, some of the more advanced programmers are developing tools so simple bash and perl scripts can interface to this nitty-gritty.

I do believe I'll do what Chris, N7ICE did and pick up the IC-91AD, instead of the IC-91AD possibly at Dayton. The extra coin saved can be later applied to purchasing a DV dongle or building Satoshi's adapter.

(Interestingly enough opendstar.org, which was the first experimental D-Star add-on that I know of has yet to live up to the open part of it's name. Hopefully they will follow suit soon and also release source code too.)

1 comment:

Steve, KB9MWR said...

I noticed Scott, KI4LKF incorporated the voice mail idea into his latest software.
http://sourceforge.net/projects/ircddb/files/ircDDB_gateway/