Problem: Accessing RX-B of the basic Rx daughterboard

GNU Radio
1

Hi!

What command should I use when I want to access the received signals at
port
RX-B of the Basix Rx daughterboard?
I have tried using usrp.source_c(1,my_block) but then an error results
saying that I cannot find usrp 1.

What I intended with that command was to access RX-B of the BASIC Rx
Daughterboard.

Your replies are greatly appreciated.

Thanks!

2

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!

3

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

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 is

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

This sets all the Q channels to zero (because of 0xf) and routes ADC1
to I1, ADC2 to I2 etc. To seperate them

On Feb 11, 2008 9:05 PM, Jason A. [email protected] 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!

–
www.stanford.edu/~karthikv

4

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 A. [email protected] 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!

–
www.stanford.edu/~karthikv