Extracting intermediate data


#1

Hello,

I am working with usrp_spectrum_sense.py and I am trying to analyze the
intermediate data from different DSP blocks.

After I passed the input stream to a vector I tried to save this
information on a file like this:

    /s2v = gr.stream_to_vector(gr.sizeof_gr_complex, self.fft_size)

    output2=gr.file_sink(gr.sizeof_gr_complex,"file2.txt")

    self.connect(self.u, s2v, output2)/

and I received the following error:

/node1-2:~/gnuradio/gnuradio-examples/python/usrp#
./usrp_spectrum_sense.py -F 16 4.5M 7.5M

Using RX d’board A: Basic Rx

Traceback (most recent call last):

File “./usrp_spectrum_sense.py”, line 305, in

tb = my_top_block()

File “./usrp_spectrum_sense.py”, line 179, in init

self.connect(self.u, s2v, output2)

File
“/usr/local/lib/python2.5/site-packages/gnuradio/gr/top_block.py”, line
70, in connect

self._connect(points[i-1], points[i])

File
“/usr/local/lib/python2.5/site-packages/gnuradio/gr/top_block.py”, line
76, in _connect

dst_block.basic_block(), dst_port)

File
“/usr/local/lib/python2.5/site-packages/gnuradio/gr/gnuradio_swig_py_runtime.py”,
line 1469, in connect

return _gnuradio_swig_py_runtime.gr_top_block_sptr_connect(*args)

ValueError: itemsize mismatch: stream_to_vector(4):0 using 128,
file_sink(5):0 using 8/

/ /

It seems to be a format mismatch.
Please any advice how to write the output of s2v to a file.

Thank you,
Catalin


#2

On Tue, 2009-01-20 at 15:33 -0500, Catalin Lacatus wrote:

    output2=gr.file_sink(gr.sizeof_gr_complex,"file2.txt")

    self.connect(self.u, s2v, output2)/

You should have written
output2=gr.file_sink(gr.sizeof_gr_complex*self.fft_size,“file2.txt”)
You are now getting vectors of 128 complex values as one item.

Success,
Martin