Re: [Discuss-gnuradio] question: how to receive from Rx-A and Rx-B of a single daughterboard

[Susumu Saito]

> Thanks for your reply!
>
> I'll try it ASAP.
>
> :)
>
>
> --- Eric Blossom <address@hidden> wrote:
>
> > On Mon, Mar 31, 2008 at 05:00:17AM -0700, James
> > Worthington wrote:
> > >
> > >
> > > I have a problem. I newly purchased a Basic Rx
> > > daughterboard and I tried using the usrp_oscope.py
> > > file to test whether or not my daughterboard
> > works.
> > >
> > > Unfortunately, only the Rx-A portion seems to be
> > > working. Is this always the case? Is there
> > something
> > > that I should do so that I could receive from the
> > Rx-B
> > > portion.
> >
> >   $ foo.py -R a:1
> >
> > > I mean, it's really weird that I have two
> > > input ports (since there are two SMA connectors
> > that
> > > serve as input to the Basic Rx Daughterboard), but
> > I
> > > can only pass input to one of them.
> > >
> > > Is the RX-B just a decoration? Could I use both
> > ports
> > > simultaneously?
> >
> > Yes.
> >
> > Try
> >
> >   $ usrp_oscope.py --help
> >
> > Eric

I use both RX-1 and RX-2 and a single Basic RX daughterboard.
ADC1 and DDC1 are used for RX-A, and ADC2 and DDC2 for RX-B.

Followings are a part of my script.

######
class wfm_rx_block (gr.top_block):
  def __init__(self,f_time,f_data):
    gr.top_block.__init__(self)

    self.state = "FREQ"
    self.freq = 0
### frequencies ###
    freq1=10000000. # 10 MHz, just for example
    freq2=12000000. # 12 MHz

### filter setup ###
    adc_rate = self.u.adc_rate()
    usrp_decim = 200
    self.u.set_decim_rate(usrp_decim)
    usrp_rate = adc_rate / usrp_decim           # 320 kS/s
    chanfilt_decim = 1
    demod_rate = usrp_rate / chanfilt_decim
    audio_decimation = 16
    audio_rate = demod_rate / audio_decimation  # 20 kHz

    chan_filt_coeffs = optfir.low_pass (1,  # gain
                               usrp_rate,   # sampling rate
                               15e3,        # passband cutoff
                               25e3,        # stopband cutoff
                               0.1,         # passband ripple
                               60)          # stopband attenuation
    audio_sink = audio.sink(int(audio_rate),
                            options.audio_output,
                            False)  # ok_to_block

#USRP with 2 channels
    self.u = usrp.source_c(0,nchan=2)

# RX-1 to DDC1, RX-2 to DDC2
    self.u.set_mux(0xf0f0f1f0)

# select RX-A daughterboard
    self.subdev = self.u.db[0]

# deinterleave two channels from FPGA
    di = gr.deinterleave(gr.sizeof_gr_complex)

# wire up the head of the chain
    self.connect(self.u, di)

    # DDC-1
    ok, baseband_freq0 = self.subdev[0].set_freq(freq1)
    # DDC-2
    ok, baseband_freq1 = self.subdev[1].set_freq(freq2)

    # DDC-1
    r0 = usrp.tune(self.u, 0, self.subdev[0],freq1)
    # DDC-2
    r1 = usrp.tune(self.u, 1, self.subdev[1],freq2)

    chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)
    self.guts = blks2.am_demod_cf (demod_rate, audio_decimation, 
15e3,25e3)
    self.connect((di,0),chan_filt)
    self.connect(chan_filt,self.guts,(audio_sink,0))

    chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)
    self.guts = blks2.am_demod_cf (demod_rate, audio_decimation, 
15e3,25e3)
    self.connect((di,1),chan_filt)
    self.connect(chan_filt,self.guts,(audio_sink,1))

######

Susumu Saito