Re: [Discuss-gnuradio] multiple antennas and multiple usrps

[Dan Halperin]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Jun 25, 2008, at 3:20 PM, Eric Blossom wrote:

> On Wed, Jun 25, 2008 at 02:37:48PM -0700, Dan Halperin wrote:
> > 1) I notice that multi-antenna.py claims to only work with the  
> > BasicRX
> > boards. Any reason I can't use the 2 RX paths on each of 2 RFX2400s
> > assuming the d'board is powered up and configured correctly?
>
> The RFX boards don't actually have two receive paths.  They have two
> antenna ports.  The boards output analog I & Q to the usrp
> motherboard, and thus two A/D's are required to handle each
> daughterboard.  With a single USRP and two RFX2400s you can handle two
> inputs and two outputs.

So what you're saying is you can't use the TX/RX and the RX2 both for  
receive at the same time? I guess that jives with the figure here:

http://gnuradio.org/trac/wiki/UsrpRfxDiagrams

Instead, that's only to enable concurrent transmit on TX and receive  
on RX2... that doesn't exactly seem that useful.

> > 2) I have a transmitter USRP and a receiver USRP attached to the same
> > machine. I use usrp.serial_number() as suggested by Eric in many
> > previous mails to distinguish between them. I have a code loop like
> > this:
>
> Are you loading a different fpga image into the different USRPs?

Yes, one is (was, I guess?) using std_4rx_0tx.rbf (see 1) and the  
other was using the default.
Thanks,

Dan

> You can get the serial numbers without actually opening them by using
> the low level usrp prims.  Take a look at usrp/host/swig/prims.i
>
>
> from usrpm import usrp_prims
>
> def get_serial_number(which):
>    d = usrp_prims.usrp_find_device(which)
>    if not d:
>        raise RuntimeError, "Unable to find USRP #%d" % (which,)
>    if usrp_prims.usrp_unconfigured_usrp_p(d):           # no  
> firmware loaded yet
>        usrp_prims.usrp_load_standard_bits(which, False) # load the  
> firmware
>    return usrp_prims.usrp_usrp_serial_number(d)


-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.8 (Darwin)

iEYEARECAAYFAkhiyFIACgkQy9GYuuMoUJ6h5QCghGbyreXs4bMYFmHtOt9fLvmw
wPIAn3sHnuUyCzKQhvuVRIfaowzz8/Dz
=GMAx
-----END PGP SIGNATURE-----