[Discuss-gnuradio] New external clock board for USRP

[Alexander Chemeris]

Hi all,

We're creating a clocking unit which will be easy to use with
USRP. If there will be enough interest from the community we
can order some amount of PCBs and put them for sale alone or
soldered and ready to use. This should be useful for everyone
trying to run OpenBTS, working with GPS and everyone else
who need to re-clock their USRP or have more clock precision.

We've created it to run USRP at 52MHz with 0.3-0.5ppm after
calibrating or 1ppm in long term without recalibrating, but actually
it will support 2.84-65.83MHz, 65.91-71.82MHz, 72.5-79MHz clock
ranges with about the same precision.

Power will be taken from USRP 6V, clock output will be SMA to
connect to USRP directly. Frequency control will be accessible
over RS-232 (aka COM-port) with simple text-based protocol. We're
going to use ATMega for this. Ideally we want tighter integration
with USRP, so it can be controlled via the same USB connection,
so you can control clocks right from GnuRadio. But to date we can't
figure out how to do this cleanly. All suggestions are welcome.

We're testing it with USRP1, but I guess it should work fine for
USRP2 too.

Estimated overall cost (including all components needed to connect
it to USRP) will be about 100$.

Please, drop me a letter if you're interested and how much units
would you buy.

-- 
Regards,
Alexander Chemeris.