On Mon, Sep 17, 2007 at 08:59:35PM +0300, Juha Vierinen wrote: > Hi, > > I am writing a simple program that stores USRP sampled data and stores > it on disk continuously in 1s sized files. I have made a new sink for > this purpose, which is almost identical to gr_filesink, except that > mine blocks in work() while the file is closed and a new one is > created. > > > 2) I have managed through trial and error to get a fairly reliable > 8MHz sampling system using the following parameters: > fusb_nblocks=32768,fusb_block_size=1024. Is this a good way to make a > large buffer or should I use some other gnuradio block to create a > large buffer in RAM?
I wouldn't recommend this. This forces the kernel to lock down 32MB of RAM, which seems like total overkill. Do you really need 1 second worth of locked down buffer? Use something like fusb_nblocks=2048, fusb_block_size=4096. Increasing the block size to 4k reduces the overhead; setting nblocks to 2048 gives 8MB of buffer (== 250ms) You could also enable real-time scheduling using gr.enable_realtime_scheduling(). > I am hoping to write the data at 8MHz on a > networked RAID array and this will cause even larger waiting times for > my filesink, even though the average bandwidth is large enough. This will probably work. > > Gnuradio and USRP is great! I really prefer your system to labview. Thanks! Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
