Rest assured that people are working on this. So far, some have reported getting an NBFM transceiver working in GNURadio. My guess is that they started the tx and rx streams and left them both running at all times.
SoDaRadio is now to the point where it can receive all day. It can transmit once or twice, but then the transmit streamer gets screwed up and, as Mr Jagger might say, "I can't get no modulation." The trouble seems to be in the transition from active to inactive (via deactivate) and then back to active (via activate). Leaving the transmit streamer active between transmissions is not an appropriate choice, as this leaves an unmodulated carrier on the TX port. (I see it quite clearly on another receiver in the shack. I am sure it will be suppressed a little more once I get the IQ balance right, but even then, 40dB is not enough when we're dealing with extremely sensitive receivers in the neighborhood.)
The community really really really needs an example program (using SoapySDR, if possible) that does this:
set frequency, sampling rate, antennas, gains...
rx_str = CreateRXStreamer
tx_str = CreateTXStreamer
FOR 1 second
collect RX buffers from streamer
FOR 1 second
transmit 1kHz tone (as an upper CW sideband)
If I could see that code actually working with SoapySDR, I'd be within hours of getting a full featured multimode VHF/UHF (and kinda HF) transceiver working with a LimeSDR.
I have looked all through the SoapySDR code, and the LimeSuite code. It seems there are no example applications that come close to this pattern. In fact, there are very few instances of code that excercises the transmit stream code/logic at all. But we know that the basic TX functioning works -- we've seen it in GNURadio and for the first happy transmissions from SoDaRadio. But clearly there are issues in the deactivate/activate transitions that either need to be fixed or need to be documented.
So far, it took just half a weekend to get the RX working. I've now put about 30 hours into the TX side and have made very very little progress. Lots of blind alleys, and a few surprising discoveries, but still having troubles with TX.
(SoDaRadio has been working as a USRP application for five years. I know the TX framework is functional. From the documentation of SoapySDR, the interface is very very similar to libUHD.)
With luck, we'll see some kind of example code soon.