[Discuss-gnuradio] Some newbie questions

[Ulf Lindgren A]

Hi,

I have been trying to understand how to make an application where I use two USRPs one acting as TX and the other as RX. Both the USRP have two RFX2400 daughter boards so I would like to transmit two streams and receive two streams. My starting point was the "fm_tx_2_daughterboards.py" which I think I understand.

First question (Tx):
 -The tx_mux setting for the top_block in  "fm_tx_2_daughterboards.py" is 0xBA98 which is understandable. If I use
      MuxVal=usrp.determine_tx_mux_value(self.u,(1,0))+usrp.determine_tx_mux_value(self.u,(0,0))
  I get 0x9898 which I do not understand.

Then I wanted to write a corresponding rx_2 and I started with the mux from the description of the rx mux, here I don't know which ADC is on RxA and RxB so I cannot figure out the appropriate setting.

In case I use
        MuxVal=usrp.determine_rx_mux_value(self.u,(0,0))+usrp.determine_rx_mux_value(self.u,(1,0));
I get 0x24, which kind of odd ? If I do
        usrp.determine_rx_mux_value(self.u,(0,1))
I get an error (I thought this meant side A Rx2)

I guess I'm all confused and don't understand the documentation, can someone please explain the Rx mux and the automatic setting?

Secondly, I tried to add a wfm modulation in the tx top_block (looking at usrp_wfm_rcv_nogui.py as receiver) and from the error message I got there is a problem with types  but unfortunately for me I don't see where and why

:
mod_rate = self.usrp_rate
audio_rate = self.usrp_rate/10
self.gutsa = blks2.wfm_tx (audio_rate, mod_rate)       
self.gutsb = blks2.wfm_tx (audio_rate, mod_rate)       

sig0 = example_signal_0(audio_rate)
sig1 = example_signal_1(audio_rate)
intl = gr.interleave(gr.sizeof_gr_complex)
self.connect(sig0, self.gutsa, (intl, 0))
self.connect(sig1, self.gutsb, (intl, 1))
:
To me it appears as if the interleaver cannot take complex inputs.

I appreciate any response to my confusion.

/Ulf