USB connectivity under gnuradio/cygwin

GNU Radio
1

I am trying to communicate with an external board (not the usrp)
using usb. I have a driver installed under Windows that works fine
with a standalone application. I have a gnuradio block for the same
board, but am unable to get the usb driver recognized under
cygwin. If someone has experience with this, I would appreciate some
insight into whether there is something special that needs to be done
to find the usb driver/port in cygwin to connect to the external
board. As an alternative can someone point me to the gnuradio code
that handles the usb connections for other boards so that I can use
this as a model for moving forward.

Thanks,
-CAS

2

On Sun, Jan 17, 2010 at 02:13:10PM -0500, CAS wrote:

Thanks,
-CAS

We use libusb to talk to the USRP.

Eric

3

Hi,

In my experimentation, the measured power depends on fft_size and
dwell_delay in usrp_spectrum_sense.py while measuring noise power, the
larger those values results in higher measured power even if it is
normalized based on the fft_size like this.

20*math.log10(math.sqrt(bin)/tb.fft_size)

  • 20math.log10(tb.fft_size)
    -10    math.log(tb.power/tb.fft_size/tb.fft_size)

I wonder it is normal operation.

Thanks,
Kyungtae