Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q

[njm25]

Thank you.  I appreciate the help.  (I actually just sent another email about 
the same problem but this solution should fix it, so you can just disregard my 
last email.)

Thanks again
Nick

----- Original Message -----
From: Eric Blossom <address@hidden>
Date: Tuesday, March 20, 2007 10:15 am
Subject: Re: [Discuss-gnuradio] Question about Basic TX/RX boards, the I, Q

> On Sun, Mar 18, 2007 at 02:46:26PM -0400, address@hidden wrote:
> 
> > It's a little confusing to me why the Basic TX does not have a
> > problem using both the I and Q channel but the Basic RX does.
> 
> Actually, there's no problem.  You can get it to do what you want 
> by explicitly specifying the rx mux value.
> 
> To feed both A side inputs into the DDC 0 as I & Q, do
> 
>  u.set_mux(0x10101010)
> 
>  /*!
>   * \brief Set input mux configuration.
>   *
>   * This determines which ADC (or constant zero) is connected to 
>   * each DDC input.  There are 4 DDCs.  Each has two inputs.
>   *
>   * <pre>
>   * Mux value:
>   *
>   *    3                   2                   1                  
>     
>   *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 
> 1 0
>   * +-------+-------+-------+-------+-------+-------+-------+-----
> --+
>   * |   Q3  |   I3  |   Q2  |   I2  |   Q1  |   I1  |   Q0  |   
> I0  |
>   * +-------+-------+-------+-------+-------+-------+-------+-----
> --+
>   *
>   * Each 4-bit I field is either 0,1,2,3
>   * Each 4-bit Q field is either 0,1,2,3 or 0xf (input is const zero)
>   * All Q's must be 0xf or none of them may be 0xf
>   * </pre>
>   */
>  bool set_mux  (int mux);
> 
> 
> 
> > It seems to me that the command "-R a:1" would tell the RX_B 
> input to
> > receive but not the RX_A input anymore.  I need both the inputs to
> > receive data at the same time, as I/Q channels connected to my RF
> > front end.  Any insights in how I do this would be much appreciated
> > (if my assumption that "-R a:1" would only have the RX_B input
> > receive).
> 
> > Thanks
> > Nick
> 
> Eric
>