Re: Problems with burn-db-eeprom

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 E. [email protected]
To: John Stralka [email protected]
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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