On Tue, Sep 15, 2009 at 04:41:39PM +0200, Ulrika Uppman wrote: > Hi all! > > I ran into the constant USRP2_MIN_RX_SAMPLES = 371 defined in > usrp2_base.h, but I don't get what it is used for (it comes with the > comment "BIG ASS FIXME: get from lower layer MTU calculation").
I believe you're referring to USRP2_MAX_RX_SAMPLES. It's the largest number of samples that will fit in a 1500 byte ethernet packet including overhead. The constant sizes some structures. (BTW, it was recently adjusted downward to 370 samples to ensure alignment for dual channel apps). > Does anyone know anything about this constant and what it affects? > ... what is depending on that it has the value 371? > (I got seg faults when trying to run less than 371 items out of a > USRP2 source block, I believe this constant has something to do with > that perhaps?) How we're you trying to do this? Hint: don't change the constant. We don't currently expose this in the gr-usrp2 interface. We do expose it in the usrp2::usrp2::start_rx_streaming interface. items_per_frame = 0 gets you the default (currently 370 or 371 depending on rev). You can set it lower if you like. usrp2_source_base::start currently passes 0 to get the default. Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
