Re: [Discuss-gnuradio] Using the dqpsk modulator

[karim]

Eric Blossom wrote:
> On Thu, Apr 09, 2009 at 09:46:43AM -0700, karim wrote:
> > Hi,
> > I am trying to use the dqpsk modulator block to modulate some data and  
> > then take the output and separate it to real and imag. This is the code,  
> >  it runs but the sinks are empty and have no data. What am I doing wrong?
>
> You're printing the contents of the vector sinks in your
> initialization code, before the graph has started running.
>
> Try printing their contents after my_top_block().run() returns.
>
> Eric

I added a function to print the sinks after I call my_top_block().run()

But the sinks are still empty. I also tried directing the output of the 
qpsk modulator to a file and it's also empty (the code below).



from gnuradio import gr, gru, modulation_utils, blks2
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser

import random, time, struct, sys, math


#no GUI
#source: stream from file_source
#connect with DQPSK: input: byte stream, output:complex
#change it to 2 parts:imagine and Real
#connect with gr.complex_to_real or gr.complex_to_imag
#display data in sink1 (real) and sink2 (imag)

class my_top_block(gr.top_block):

  def __init__(self):
    gr.top_block.__init__(self)

    src_data = (1,0,1,0,1,0,1,0)
    src = gr.vector_source_b (src_data)

    #input: unsigned char, output: complex
    qpsk = blks2.dqpsk_mod(2,.35,True, False, False)
    self.connect (src,qpsk)

    real = gr.complex_to_real()
    imag = gr.complex_to_imag()
    self.connect(qpsk,real)
    self.connect(qpsk,imag)

    self.sink1 = gr.vector_sink_f()
    self.sink2 = gr.vector_sink_f()

    self.connect(real,self.sink1)
    self.connect(imag,self.sink2)

    qpsk_file_op=gr.file_sink(gr.sizeof_gr_complex, "qpsk_op.dat")

    self.connect(qpsk,qpsk_file_op)


  def print_data(self):
    print "Data in sink1 is: ",self.sink1.data()
    print "Data in sink2 is: ",self.sink2.data()


if __name__ == '__main__':
    try:
        my_top_block().run()
        my_top_block().print_data()
    except KeyboardInterrupt:
        pass