[Discuss-gnuradio] Problem receiving RX-A and RX-B simultaneously

[Eduardo Lloret Fuentes]

Hello,

I programmed a module into the FPGA that is able to process separately two independent signals at the same time with the LFRX. Using and external oscilloscope and the LFTX I checked that it works properly.

Now, I tried to check the output on the PC side using tools like fft_sink_c or scope_sink_c but I found several problems. My graph implements two blocks at the output of the USRP2 source: a "complex to real()" and a "complex_to_imag()". I thought that I would get the 'I' and 'Q' doing this. I connected each output to a FFT Sink with float inputs but the plot I get only depends on the RX-A input.

Later, I also read that setting the "is_quadrature" value to 'true' in the file named db_basic.c (http://gnuradio.org/cgit/gnuradio.git/tree/usrp2/firmware/lib/db_basic.c?h=next#n123) could work but what I got is that I have the same plot for 'I' and 'Q'.

I am using Ubuntu 10.10 and GNU Radio driver. Any help would be great!

Thanks!

Eduardo.