Re: [Discuss-gnuradio] Time of Arrival Hooks

[Tim Pearce]

Doug,

Thanks I'll try this. Googling a bit more I think fwrite has to be thread safe, I'll double check my setup again and have another think if this doesn't help.

Cheers,

Tim

On Thu, Nov 19, 2009 at 7:17 PM, Doug Geiger <address@hidden> wrote:

Tim Pearce wrote:

Hi Guys,

After experimenting a bit more I think the issue was my test setup.

Previously I was using python to setup a USRP Source (with timestamps) and save both the samples (64 bit) and timestamps (32bit) to a file sink to process by importing with numpy and checking timestamps later.

At 25MHz thats ~ 300MB/sec of data, which is substantially more than machines disk, which is probably about 20MB/sec max.

Don't have a good answer on the thread-safety question - but one method I've used when I want to collect a bunch of data for a limited period of time is mount a ram disk/tmpfs. E.g. I'd do something like:
$ mkdir /tmp/shm
$ sudo mount -t tmpfs tmpfs /tmp/shm
$ usrp2_rx_cfile -e <interface> -f <frequency> -N <big number here> /tmp/shm/data.dat

Cheers,

Tim

Doug

--
Douglas Geiger
Code 5545
U.S. Naval Research Laboratory
Washington, DC 20375
(202) 767-9048
address@hidden