Re: [Discuss-gnuradio] Problems with burn-db-eeprom

[John Stralka]

Matt,
 
<< First off, reburning the eeprom is the LAST step in several step process to 
make an RFX board into a MIMO_A board. >> ... yes, as I mentioned in my post 
from 7/30/07, I made the modifications that you provided in a post from 2/7/07, 
where you stated:
 
        All RFX boards currently shipping are configured for MIMO_B mode, which
        requires a Rev 4 or higher USRP (serial number greater than 500).

        If you wish to use it with a USRP with a serial number below 500 you
        will need to do the following:

                Remove R115 (zero ohms) and place it at R116
                Remove R36 (zero ohms) and place it at R34
                Put the RFX on a USRP (side A) and run the following:
                       usrp/host/apps/burn-db-eeprom -f -A -t rfxYYYY_mimo_a
                    where YYYY is the board you have (i.e. 400, 900, 1200, 
1800, or 2400).

<< Secondly, why are you doing this?  You have MIMO_B boards which is the 
optimal setup.  The only reason to make a mimo_a board is if you want to use it 
with a very old rev 3 USRP, which you do not have. >> ... I'm trying to create 
a comm link between two RFX2400 daughterboards.  I noticed that there is a 
significant amount of RF leakage between two daughterboards within the same 
USRP enclosure.  Therefore, I wanted to seperate them into two separate USRP's. 
 I have an USRP with a Rev 4 PCB (2/17/07, Ser #1263) .  The only other USRP 
that I have access to has a Rev 3 PCB (1/3/05, Ser #409), which according to 
your 2/7/07 post requires the corresponding RFX2400 to be modified for MIMO_A 
operation.

Is this correct?
 
In order to use one of my RFX2400 daughterboards with the Rev 3 USRP I have 
successfully done the following:
    
    Remove R115 (zero ohms) and place it at R116
    Remove R36 (zero ohms) and place it at R34
    Put the RFX on a USRP (side A) and run the following:
        usrp/host/apps/burn-db-eeprom -f -A -t rfx2400_mimo_a
 
I can transmit from the Rev 3 USRP, but I cannot receive on it.  It seems to 
have a tuning problem.
 
I would appreciate any help.  Thank you.
 
                            John


----- Original Message ----
From: Matt Ettus <address@hidden>
To: John Stralka <address@hidden>
Sent: Tuesday, August 14, 2007 12:48:15 PM
Subject: Re: [Discuss-gnuradio] Problems with burn-db-eeprom


John Stralka wrote:
> I reinstalled the trunk version of GNU Radio, and I was able to successfully 
> burn the RFX 2400 to MIMO A.  The problem I have now is that I cannot seem to 
> get the daughterboard to tune on receive in either a Rev 3 USRP or a Rev 4 
> USRP.  I've verified that it is reporting MIMO A in the USRP Diagnostics 
> within GRC, but when I run usrp_fft.py on the MIMO A board, I get "Failed to 
> set initial frequency".  
>
> I tried putting at MIMO A (side B)  and a MIMO B (side A) RFX 2400 in a 
> single Rev 4 USRP.  Interestingly, I am able to transmit a tone via a MIMO A 
> card and receive it in a MIMO B card.  But I cannot receive the tone 
> transmitted by the MIMO B card on the MIMO A card due to this "Failed to set 
> initial frequency" problem.  The MIMO B board's tone is fine.  This is how I 
> was testing them.
>      ./usrp_fft.py -R B -d 256 -f 2.4375e9 -g 10  & ./usrp_siggen.py -f 
> 2.437550e9 -i 512 --const -T A
>
> When I burned the MIMO A card, I used the following command:
>      ./usrp/host/apps/burn-db-eeprom -f -A -t rfx2400_mimo_a
>
> Is there something I should check?  I'm at a loss on how to proceed.  Any 
> suggestions would be appreciated.  Thank you.
>   

First off, reburning the eeprom is the LAST step in a several step
process to make an RFX board into a MIMO_A board.  The rest of the
procedure is shown here:

    http://gnuradio.org/trac/wiki/USRPClockingNotes

Secondly, why are you doing this?  You have MIMO_B boards which is the
optimal setup.  The only reason to make a mimo_a board is if you want to
use it with a very old rev 3 USRP, which you do not have.

Matt


      
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