|From:||Anderson, Douglas J.|
|Subject:||Re: [Discuss-gnuradio] voltage pulse from UHD driver|
|Date:||Thu, 15 Jan 2015 17:46:14 +0000|
Okay, this makes sense.
What about the version I posted on StackExchange where I am using GNU Radio's scheduler to request the samples?
What does GNU Radio do when running a constant flowgraph (like uhd_fft) that it doesn't to when running topblock.run() for each collection, as far as discarding samples off the front?
From: Nick Foster address@hidden
Sent: Thursday, January 15, 2015 10:40 AM
To: Anderson, Douglas J.
Cc: GNURadio Discussion List
Subject: Re: [Discuss-gnuradio] voltage pulse from UHD driver
In general you cannot use the first few samples of output from an acquisition. There are a couple of reasons:
First, if you begin collecting data immediately (rather than using UHD to schedule a collection at a given time) and you are using a daughterboard with a downconverter (anything but BasicRX or LFRX), tuning takes some time and things will be ugly while PLLs settle, etc.
Second, there are digital halfband and CIC filters in the USRP, and they are not reset between acquisitions. This means that the first samples will have some junk left over from the last acquisition.
Unfortunately, the general answer to what you're trying to do is, don't do that.
On Thu, Jan 15, 2015 at 9:26 AM, Anderson, Douglas J. <address@hidden> wrote:
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