Implement DSD "demodulator" with gr-dsd

[kpreid]

Implement DSD "demodulator" with gr-dsd

[kpreid]

That was fairly easy. Done in commit ec83231.

Unfortunately, dsd.block_ff has a severe lack of methods: it neither allows changing the parameters live (only at block construction time) nor reading back any status information about whether it is successfully demodulating (such as dsd internally prints to stdout), so you have to use it sort of blind (other than hearind the audio). If you're interested in this feature, please consider suggesting/contributing such improvements to upstream dsd / gr-dsd.

[turnrye]

Wow, awesome work. This was not quite the path I started down for implementation, so I'm glad you came in to help. I've successfully got this working on my install, which is using ubuntu 14.04. Note that gr-dsd installs to the wrong directory, so you must cp -r /usr/lib/lib/* /usr/lib to resolve that (or else import dsd fails).

[kpreid]

I had to use a different version, too. That's why I didn't link anything in the README — I'll wait for upstream to get its act together before saying who's upstream.

It would be informative to hear what “path you started down”. (Adding an option to the basic FM demodulator?) ShinySDR is not exactly ideally architected and I'd like to know what looked like a good idea because there's always a chance it might be a better idea in the long run.