Re: [Discuss-gnuradio] Problem: Accessing RX-B of the basic Rx daughterboard

[Karthik Vijayraghavan]

Jason,

Ah this is exactly what I have been grappling with as well. Basically
you need to set the MUX _such that_ you can access the two setting
simultaneously. If you have the gnuradio source you, look at the file
gnuradio-examples/multi-antenna/multi_scope.py which tells you how you
can look at 4 signals at the same time using two BASIC-RX boards.For
more than one signal, you can no longer use the
usrp.determine_rx_mux_value(u,rx_subdev_spec) method. Instead you have
to set the MUX by hand. The crucial line in the example code is.

self.u.set_mux(gru.hexint(0xf3f2f1f0))

This sets all the Q channels to zero (because of 0xf) and routes ADC0
to I0, ADC1 to I1 etc. To separate them  you have the line

gr.deinterleave(gr.sizeof_gr_complex)

I have yet to try this out on my own program, but that is as far as I
understand it. I believe If you want to get 4 signals simultaneously
you need load a special FPGA image file, the details of which are
shown in the example. However for getting only 2 signals the standard
FGPA config is good enough (there is an earlier post on this somewhere
in the archive). Maybe others can correct me if I am wrong.

Karthik



On Feb 11, 2008 9:05 PM, Jason Anders <address@hidden> wrote:
>
> Hi! Thanks for your reply. It was helpful!
>
>  However, I have another follow-up question. So, basically I won't be able
> to access RX-A and RX-B simultaneously since I have to set the MUX
> everytime? Is this correct?
>
>  Thanks!
>



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