Getting samples from Gnuradio to c++

GNU Radio
1

Can anyone please help me?

I want to capture samples from Gnuradio and get them to a c++
application in real-time. I then want to calculate the ambiguity
function and display it on a contour plot. What is the best way to do
this? What I have in mind is to use Qwt with Qt for this, but then I
will need to get the samples to c++ in real-time.

Thank you very much.

Sebastiaan H.

2

Sebastiaan H. wrote:

Can anyone please help me?

I want to capture samples from Gnuradio and get them to a c++
application in real-time. I then want to calculate the ambiguity
function and display it on a contour plot. What is the best way to do
this? What I have in mind is to use Qwt with Qt for this, but then I
will need to get the samples to c++ in real-time.

Write your samples to a UDP_sink, with the packets addressed to
localhost (127.0.0.1). Then you can write a simple UDP reader
in C++ to get the data in realtime.

@(^.^)@ Ed

3

On Mon, Jun 16, 2008 at 10:31:51AM -0400, Ed Criscuolo wrote:

Write your samples to a UDP_sink, with the packets addressed to
localhost (127.0.0.1). Then you can write a simple UDP reader
in C++ to get the data in realtime.

– or –

Use usrp_rx_cfile and specify a file that goes somewhere you like.
E.g., a named pipe (see man mkfifo), or you could write to stdout on
Linux like this:

$ usrp_rx_cfile -R A -f -d -g /proc/self/fd/1 |
my-c+±app

[We could of course change the interface so that it would write to
stdout if no file was specified…]

Eric

4

Hi,

To process data in C++ coming from the USRP in real time, See:

http://gnuradio.org/trac/wiki/UsrpFAQ/CppInterface

Regards,

Firas

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5

You can create a named pipe with mkfifo /tmp/fifo. Connect your gnuradio
stream to a gr.file_sink(item_size, ‘/tmp/fifo’). And in your c++
program, you can read from the fifo just like a regular file.

-Josh