Re: [Discuss-gnuradio] How to use several DDC in usrp?

[Josh Blum]

On 05/26/2013 01:10 PM, Wolfgang Buesser wrote:
> Hello
> 
> I am using a usrp1 populated with 2 LFRX and 2 LFTX daughter boards.
> 
> I want to use the 2 ADC of LFRX-A to sample s different signals.
> 
> To do this I use set_subdev_spec("A:A B:A",0).
> 
> In order to avoid a segmentation fault I apparently have to create the rx 
> with num_channels=2.
> 
> But now I get the error-message:
> 
> 
> RuntimeError: gr uhd usrp source(4): insufficient connected output ports (2 
> needed, 1 connected) 
> 
> My questions:
> 1) Is the num_channels argument to uhd.usrp_source specifying the number of 
> active DDCs?
> 
> 2) How do I connect more than 1 port to uhd.usrp_source? In pre-uhd this was 
> achieved using gr.deinterleave - but this does not seem to work anymore.
> 

The block has 2 output ports in this case.

-josh

> Here is the code:
> 
> #!/usr/bin/python                                                             
>                                                                               
>                                                                               
>                                    
> 
> from gnuradio import gr
> from gnuradio import uhd
> from gnuradio.eng_option import eng_option
> 
> 
> class build_block(gr.top_block):
>     def __init__(self):
>         gr.top_block.__init__(self)
> 
>         self.u_tx = uhd.usrp_sink("serial=47432785",uhd.stream_args('fc32'))
>         self.siggen_tx = 
> gr.sig_source_c(self.u_tx.get_samp_rate(),gr.GR_CONST_WAVE,0, 1.0, 0)
> #        self.head_tx   = gr.head(gr.sizeof_gr_complex, 1000000)              
>                                                                               
>                                                                               
>                                    
>         self.head_tx   = gr.head(gr.sizeof_gr_complex, 1000)
>         self.u_tx.set_subdev_spec("A:AB",0)
>         self.u_tx.set_center_freq(10e6)
>         self.u_tx.set_samp_rate(1e6)
>         self.u_tx.get_samp_rate()
> 
> 
> #        self.u_rx = 
> uhd.usrp_source("serial=47432785",uhd.stream_args('fc32'),num_channels=1)     
>                                                                               
>                                                                               
>               
>         self.u_rx = 
> uhd.usrp_source("serial=47432785",io_type=uhd.io_type.COMPLEX_FLOAT32,num_channels=2)
> #        self.u_rx.set_subdev_spec("A:A B:A",0)                               
>                                                                               
>                                                                               
>                                    
>         self.u_rx.set_subdev_spec("A:A B:A",0)
>         self.u_rx.set_center_freq(10e6+1e3)
>         self.u_rx.set_samp_rate(250e3)
>         self.head_rx_0 = gr.head(gr.sizeof_gr_complex, 1000)
>         self.dst0 = gr.file_sink(gr.sizeof_gr_complex, "r.dat")
> 
> #       self.di = gr.deinterleave(gr.sizeof_gr_complex)                       
>                                                                               
>                                                                               
>                                    
> 
> #        self.connect (self.siggen_tx,self.head_tx, self.u_tx)                
>                                                                               
>                                                                               
>                                    
>         self.connect (self.u_rx,self.head_rx_0,self.dst0)
> #        self.connect (self.u_rx,self.di)                                     
>                                                                               
>                                                                               
>                                    
> 
> tb = build_block ()
> tb.run ()
> 
> Thanks
> 
> Wolfgang
> 
> 
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>