[Discuss-gnuradio] UHD Announcement - March 18th 2011

[Josh Blum]

Hello list,

New code has been pushed to master and new images have been uploaded.
This effects USRP2, USRP-N210, and USRP-E100.
http://www.ettus.com/downloads/uhd_images/UHD-images-most-recent/

E100 Users: expect a follow-up announcement for an updated kernel and
instructions.

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-- Stability
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The gr-uhd component is now part of the gnuradio master branch; the
gnuradio-master branch and the uhd master branch are now compatible.

At this point, we intend to keep the master branch of UHD stable. The
master branch will only be changed for bug fixes, and new hardware
support. Other than that, API and implementation code will not be changed.

After an initial trial period to discover bugs and provide fixes, we
plan to provide UHD installers for the various platforms (rpm, deb, exe).

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-- New feature - second DDC in USRP2 and N210
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The USRP2 and N210 now features a second receiver chain the FPGA. This
will allow one to simultaneously receive from daughterboards with
multiple subdevices (Ex: Basic-RX, TVRX2). Or, have two channels with
different frequency offsets on one subdevice. Both channels will have
the same sample rate.

To use the second receiver, set the appropriate RX subdevice
specification. For example, to get get subdevice A on channel 0 and
subdevice B on channel 1 on a BasicRX, use ":A :B". The behavior is
identical for anyone using multi channel UHD on a USRP1.

There is also a multi-channel receive example in uhd:
http://code.ettus.com/redmine/ettus/projects/uhd/repository/revisions/master/entry/host/examples/rx_multi_samples.cpp

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-- New feature - jumbo frames with USRP2 and N210
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After some refactoring of the buffering in the device, we have not only
freed additional block rams, but the internal buffering now supports
larger frames sizes up to 4K. In order to use jumbo frames, you must
have an ethernet card that supports the large frame size. Usually this
can be set with ifconfig <dev> mtu <size>

The default frame size will not exceed 2K unless the user overrides this
with special transport options:
http://www.ettus.com/uhd_docs/manual/html/transport.html#udp-transport-sockets

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Testing and feedback is always welcome!

Thanks,
-Josh