[Discuss-gnuradio] Re: Read samples from two channels and write to file

[Diana Iosifescu]

I tryed your code, but it's not working. I get a lot of errors.
This is the complete program i have written(I've modified the 
multi-fft.py file with the lines you wrote me).
Can you explain what this line does:
rx_subdev = self.rx_src.db[0]+self.rx_src.db[1]? The numbers 0 and 1 
refer to inputs from the same Basic RX or to different Basix Rx boards? 
I have connected only one Basic Rx.
Thank you very much for your help,
Diana

#!/usr/bin/env python
from gnuradio import gr, gru, eng_notation
from gnuradio import usrp
from gnuradio.eng_option import eng_option
from gnuradio import eng_notation
from gnuradio import optfir
from optparse import OptionParser
from gnuradio.wxgui import stdgui, fftsink2, waterfallsink, scopesink, 
form, slider
import wx
from usrpm import usrp_dbid
import time
import os.path
import sys
class my_graph(stdgui.gui_flow_graph):

    def __init__(self, frame, panel, vbox, argv):
        stdgui.gui_flow_graph.__init__(self)

        self.frame = frame
        self.panel = panel
    usage="%prog: [options]"
        parser = OptionParser (option_class=eng_option,usage=usage)
        #parser.add_option("-S", "--subdev", type="subdev", default=(0, 
None),
        #                  help="select USRP Rx side A or B 
(default=A)")
        parser.add_option("-d", "--decim", type="int", default=128,
                          help="set fgpa decimation rate to DECIM 
[default=%default]")
        parser.add_option("-f", "--freq", type="eng_float", 
default=10.7e6,
                          help="set frequency to FREQ 
[default=%default])", metavar="FREQ")
        parser.add_option("-g", "--gain", type="eng_float", default=0,
                          help="set gain in dB [default=%default]")
        parser.add_option("-F", "--filter", action="store_true", 
default=True,
                          help="Enable channel filter")
        (options, args) = parser.parse_args()

        if len(args) != 1:
            parser.print_help()
            raise SystemExit,1

    n_chans = 2
    fftsize_N=512
    if options.filter:
            sw_decim = 4
        else:
            sw_decim = 1

    self.rx_src = usrp.source_c()

    if self.rx_src.nddc() < n_chans:
            sys.stderr.write('This code requires an FPGA build with %d 
DDCs.  This FPGA has only %d.\n' % (n_chans, self.rx_src.nddc()))
            raise SystemExit,1

    if not self.rx_src.set_nchannels(n_chans):
            sys.stderr.write('set_nchannels(%d) failed\n' % (n_chans,))
            raise SystemExit,1

        rx_rate = self.rx_src.adc_freq() / self.rx_src.decim_rate()
        print "USB data rate   = %s" % 
(eng_notation.num_to_str(rx_rate),)
        print "Scope data rate = %s" % 
(eng_notation.num_to_str(rx_rate/sw_decim),)

    rx_subdev = self.rx_src.db[0]+self.rx_src.db[1]

    self.rx_src.set_mux(gru.hexint(0xf1f0f3f2))

    deinterleaver = gr.deinterleave(gr.sizeof_gr_complex)

    for i in range(nchan):
           scope = fftsink.fft_sink_c(self, panel, 
sample_rate=input_rate/sw_decim,
                                     title="Input %d" % (i,),
                                    ref_level=80, y_per_div=20)
      vbox.Add(scope.win, 10, wx.EXPAND)
    for i in range(n_chans)
      self.rx_src_fft0 = 
fftsink2.fft_sink_c(panel,title="ChRXB-A",fft_size=fftsize_N,sample_rate=rx_rate/sw_decim)
      vbox.Add(self.rx_src_fft0.win,10,wx.EXPAND)
    for i in range(n_chans)
      self.rx_src_fft1 = 
fftsink2.fft_sink_c(panel,title="ChRXB-B",fft_size=fftsize_N,sample_rate=rx_rate/sw_decim)
      vbox.Add(self.rx_src_fft1.win,10,wx.EXPAND)

    self.connect(self.rx_src,deinterleaver)

    self.connect((deinterleaver,0),self.rx_src_fft0)
    self.connect((deinterleaver,1),self.rx_src_fft1)



    chan_filt_coeffs = optfir.low_pass (1,           # gain
                                            rx_rate,  # sampling rate
                                            80e3,        # passband 
cutoff
                                            115e3,       # stopband 
cutoff
                                            0.1,         # passband 
ripple
                                            60)          # stopband 
attenuation
        #print len(chan_filt_coeffs)


    self.set_gain(options.gain)
        self.set_freq(options.freq)

    def set_gain(self, gain):
        for i in range(len(self.subdev)):
            self.rx_subdev[i].set_gain(gain)
  #Tune the receiver
  def set_freq(self, target_freq):
        ok = True
        for i in range(len(rx_subdev)):
            r = self.rx_src.tune(rx_subdev[i]._which, i, rx_subdev[i], 
target_freq)
            if not r:
                ok = False
                print "set_freq: failed to set subdev[%d] freq to %f" % 
(i, target_freq)

        return ok

def main ():
    app = stdgui.stdapp(my_graph, "Multi Scope", nstatus=1)
    app.MainLoop()

if __name__ == '__main__':
    main ()
Karthik Vijayraghavan wrote:
> On Wed, Apr 23, 2008 at 5:38 AM, Diana Iosifescu <address@hidden> 
> wrote:
>>  Diana
>>  --
>>  Posted via http://www.ruby-forum.com/.
> 
> I recently finished doing exactly this. The following code works for
> me. I modified this from the multi_fft example file.
> 
> n_chans = 2;
> self.rx_src = usrp.source_c()
> rx_subdev = self.rx_src.db[0]+self.rx_src.db[1]
> self.rx_src.set_mux(gru.hexint(0xf1f0f3f2))
> deinterleaver = gr.deinterleave(gr.sizeof_gr_complex)
> self.rx_src_fft0 =  fftsink2.fft_sink_c(panel,title="Ch
> RXB-A",fft_size=fftsize_N,sample_rate=rx_rate/sw_decim)
> self.rx_src_fft0 =  fftsink2.fft_sink_c(panel,title="Ch
> RXB-B",fft_size=fftsize_N,sample_rate=rx_rate/sw_decim)
> 
> self.connect(self.rx_src,deinterleaver)
> self.connect((deinterleaver,0),self.rx_src_fft0)
> self.connect((deinterleaver,1),self.rx_src_fft1)
> vbox.Add(self.rx_src_fft0.win,10,wx.EXPAND)
> vbox.Add(self.rx_src_fft1.win,10,wx.EXPAND)
> 
> #Tune the receiver
> for i in range(len(rx_subdev)):
>        r = self.rx_src.tune(rx_subdev[i]._which, 
> rx_subdev[i],carrier_freq)
>        if not r:
>             print "set_freq: failed to set subdev[%d] freq to %f" %
> (i, carrier_freq)
> 
> 
> RXB-A appears on (deinterleaver,0) ad RXB-B appears on
> (deinterleaver,1). If you are using RXA then you might want to replace
> the mux value by something like 0xf3f2f1f0.
> 
> Regards,
> Karthik
> 
> --
> www.stanford.edu/~karthikv

-- 
Posted via http://www.ruby-forum.com/.