Hi, you might have noticed some movement on the gr-uhd component recently. Here's a quick update what's happening:
Least importantly, there was some refactoring to reduce the amount of duplicated code between usrp_sink and usrp_source. It's very unlikely this will affect anyone, unless you have custom patches to these blocks. This was merely a requisite for being able to do further changes. The big change for the moment is the enhanced message interface. With more blocks using messages for commands (not just data), we're trying to standardize how blocks receive messages. If you build the manual yourself, you'll see the changes added in https://github.com/mbr0wn/gnuradio/commit/72e0c237e06e5214eb2706bd4ac732cef068161c to document how we'd like these command interfaces to look like. UHD already had it's own, home-grown message command interface. With this change, it has been adapted to comply with how command messages should look like. At the same time, a lot of new commands were added. You can now change gain, antenna, DSP frequency, LO offset, command times, analog bandwidth (where applicable) and sampling rate through messages. This offers tons of cool new options. Imagine you have a blind OFDM receiver, which first estimates the OFDM parameters (center frequency, bandwidth, sampling rate) before attempting to blind-demodulate. You can have a downstream block change all of these parameters[1] in a kind of control loop[2] until they match, then demodulate -- all from the same flow graph, just using GNU Radio blocks. The flipside of this new swath of options is that I haven't tested it very thoroughly. There's just way too much to test, and I'd rather have it out there sooner than later. Of course, all the new commands are understood and acted upon, and most importantly, *nothing that previously worked was changed in functionality and/or API*. So, all these changes are backward-compatible. These changes have just entered our ever-full PR FIFO, so it's not yet in master. If you're interested in checking it out before that, see here: https://github.com/mbr0wn/gnuradio/tree/uhd/message_updates There's some more changes in the pipeline, but I'm happy to get feedback on this stage. Have fun, Martin [1] To change the sampling rate arbitrarily, you'll need an AD9361-based device, e.g. the B210 [2] In a true control loop, you have precise control over the feedback delay, which you don't have with async messages. However, some of these values create tags when changed, so at least you get precise timing information feedback _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
