Re: [Discuss-gnuradio] Problems with 2 RX

[Eric Blossom]

On Wed, May 09, 2007 at 01:02:52PM +0200, Albert Rodriguez wrote:
> Hi everyone!
> We're trying to receive two signals from two different RFX2400 in the
> same USRP. We've already read everything about setting the rx mux and
> the n_channels. However, we still cannot receive the two signals
> correctly.
> When we put signal in the first Rx1 (that goes to one RFX2400), we can
> see it, but we cannot see the other in Rx2 (to the other RFX2400),
> it's like it hasn't any kind of input signal. I add the code. We don't
> know if it's a problem of the deinterleave, or the mux. Thanks in
> advance
> 
> class my_graph(stdgui.gui_flow_graph):
> 
>    def __init__(self,frame,panel,vbox,argv):
>       stdgui.gui_flow_graph.__init__ (self,frame,panel,vbox,argv)
> 
>       sample_rate = 320000
>       freq = 2450000000                               
>       usrp_decim = 200
>       decim = 10
> #USRP
>       src = usrp.source_c(0, usrp_decim, fpga_filename="std_2rxhb_2tx.rbf")
>       src.set_mux(gru.hexint(0x32103210))
>       src.set_nchannels(2)    
>       subdev_spec1 = (0,0)
>       subdev_spec2 = (1,0)
>       subdev1 = usrp.selected_subdev(src, subdev_spec1)
>       subdev2 = usrp.selected_subdev(src, subdev_spec2)
>       subdev1.set_auto_tr(True)
>       subdev2.set_auto_tr(True)       
>       subdev1.select_rx_antenna('RX2')        
>       subdev2.select_rx_antenna('RX2')        

These lines:

>       r=src.tune(0,subdev1,freq)
>       r=src.tune(0,subdev2,freq)

Should be:

>       r=src.tune(0,subdev1,freq)
>       r=src.tune(1,subdev2,freq)

BTW, checking the return value is always a good idea ;)


>       self.fft_1=fftsink.fft_sink_c(self,panel,0,10,50,sample_rate,512,2)
>       self.fft_2=fftsink.fft_sink_c(self,panel,0,10,50,sample_rate,512,2)
>       di=gr.deinterleave(gr.sizeof_gr_complex)
>       fg = gr.flow_graph ()
>       
>       self.connect (src,di)
>       self.connect ((di,0),self.fft_1)
>       self.connect ((di,1),self.fft_2)
>       self._build_gui(vbox)
> 
>    def _build_gui(self, vbox):
> 
>       vbox.Add(self.fft_1.win, 10, wx.EXPAND) 
>       vbox.Add(self.fft_2.win, 10, wx.EXPAND)         
> 
> if __name__ == '__main__':
>    app = stdgui.stdapp (my_graph, " ")
>    app.MainLoop ()