Re: [Discuss-gnuradio] Tx Signal time

[Eric Blossom]

On Fri, Mar 16, 2007 at 10:10:28AM +0100, anmar wrote:
> hi,
> 
> How can i set the time of the signal between sin and cos.
> in the file test_usrp_standard_tx.cc when i change  the ampl the ampl
> changes.
> pattern[2*i+1] = host_to_usrp_short ((short) (ampl * sin (2*M_PI*i
> /PERIOD)));
> but when i change it to
> pattern[2*i+1] = host_to_usrp_short ((short) (ampl * sin (2*M_PI*i
> /PERIOD+or- X))); nothing happens, the signal stay normal Sin.
> 
> if this is not the place to change the signale output where should i
> look at.
> in python we can chose sin, cos or const. but nothing in between .
> 
> how can i do that?
> 
> Thanks,
> 
> Anmar

First off I suggest that you not use test_usrp_standard_tx.cc as an
example to emulate.  It doesn't handle daughterboards, and was
originally written to test the USRP before the rest of the GNU Radio
framework was written.

You can generate pretty much anything from python.  I'm not sure what
you are looking for.  If you want to independently genereate the real
and imaginary components of the complex baseband signal, you are free
to do that.  You can then combine the two float streams into a complex
stream using

  u = usrp.sink_c(...)

  i = <generate I somehow>
  q = <generate Q somehow>
  f2c = gr.float_to_complex()
  fg.connect(i, (f2c, 0))
  fg.connect(q, (f2c, 1))
  fg.connect(f2c, u)

Eric