Re: [Discuss-gnuradio] Re: New external clock board for USRP

[Alexander Chemeris]

On Tue, Oct 20, 2009 at 18:29, Jason <address@hidden> wrote:
> Alexander Chemeris wrote:
>> As I wrote in my previous mail, we're working on an universal clock
>> source for USRP (and not only for USRP). It is based on 0.28ppm TCXO
>> from Connor Winfield [1], National Semiconductor LMX2531 VCO+PLL [2]
>> and LMK01000 CD [3] for clock generation and Atmel ATUSB for control.
>> So far we've finished PCB design and working on production of the first
>> 25 units. We'll reserve 5 of them for our own use and testing of
>> different options, 8 others are requested by community people, so there
>> are more then 10 left for sale. We plan to finish production at
>> the beginning of Dec and take units to 26C3. If you plan to attend it,
>> you have a great chance to see them, play with them and take some of
>> them with you. ;)
>>
>
> Awesome!  I don't think I'll be able to swing 26C3, though.
>
>> As we promised, units form this experimental batch will be sold out
>> for only $100 or 66EUR (without shipping). We kindly invite everyone
>> interested in such unit to get one and try fitting it to your setup.
>> Also we need your help determining the best feature set for the unit
>> (read on for the ample list of possible features). We aim at creating
>> a really flexible and cheap clocking unit, which may used by a broad
>> GnuRadio community and will best fit its needs. Unit with open source
>> software and open hardware.
>>
>
> Can you post the preliminary pcb/gerber/asm files?  Are you using geda/pcb,
> by chance?

We will setup a website for the project and will put sources and schematics
there. To date software is in embryo stage - we were busy placing unit
into production to get it before 26C3. We plan to get back to it soon and
will publish it then.

>> Now, lets get to facts. Board dimensions are 86x44mm (3.4" x 1.7") -
>> it is designed to work inside of USRP box with RFX boards installed
>> with no external connections.
>>
>> Default distribution version includes:
>> 1) Clock board with default options
>> 2) U.FL to SMA cable to connect to USRP
>> 3) Power cable to connect to USRP's fan connector
>>
>> Default board options:
>
> [snip]
>>
>> 12) 1pps external signal may be used to tame the clock to external
>> GPS unit. It will be passed to ATMega's interrupt input, so you
>> should keep in mind that this will need a lot of software work for
>> filtering
>> out jitter, generated by it. We don't plan to develop this software at
>> least now, but anyone who need this is welcome to take it.
>>
>
> This would be interesting.

You're welcome to get the unit and hack this ;)


-- 
Regards,
Alexander Chemeris.