[Discuss-gnuradio] Help wanted with building a block

[Bob Cowdery]

 Hi,

I've just started investigating the possibility of building a
source/sink to a USB device. I've read the 'How to Write a Signal
Processing Block', built GNURadio on Ubuntu 10.04 and played around a
bit with building the example gr-how -to-write-a -block. I've also had a
cursory look at the usrp directories. I'm looking for a little bit of a
leg-up to kick me off. I'm assuming that the structure of the usrp2
directories would be the best place to start. I have noticed that the
document 'How to Write a Signal Processing Block' shows a different
directory structure to that in the code example and the usrp directories
are different again. There is also a gr-usrp2 and usrp2 and it's not
immediately obvious to me how they are split up and why.

1. Which would be the best structure to take as a template and do I need
both structures as in usrp2.
2. Most of the documentation talks about processing blocks,  sources and
sinks.  Is there anything that talks about a device which is both a
source and a sink or do I need to trawl through the usrp code to see how
to handle that.

Regards
Bob