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Re: [Discuss-gnuradio] switching between signal and reference source
From: |
Marcus D. Leech |
Subject: |
Re: [Discuss-gnuradio] switching between signal and reference source |
Date: |
Thu, 15 Apr 2010 20:19:29 -0400 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 |
>
> On Thu, Apr 15, 2010 at 16:52, Marcus D. Leech <address@hidden> wrote:
>
>
> If you are willing to give up an LSB, you can turn on GPIO streaming
> with enable_gpio_streaming(). Then io_rx[15] will show up in the lsb
> of I, and io_rx[14] will show up in the lsb of Q. You need to use the
> usrp2.source_16sc source to get the raw samples, then gr_and_const to
> separate the digital bit from the rest of the sample.
>
> The io bits get stuffed as the samples come out of the DDC, so there
> is a fixed offset (you'll need to measure it) based on the group delay
> through the whole analog front-end and FPGA DDC. The delay is
> decimation dependent, but deterministic.
>
> Johnathan
>
>
>
OK, so Josh, how do you get access to usrp2.source_16sc from GRC?
--
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org