John- > I have a USRP2 and I'm interested in doing an experiment where I'd like to > simply use the USRP2 as an A/D and D/A device, essentially disabling the RF > tuning portions. The signal I'm trying to digitize is a stream of digital > TTL pulses. I assume that the best way to interface to this is through the > DC-30MHz LFTX and LFRX daughtercards that would pass DC. Could anyone > provide me with additional guidance on how to run this test? Thanks in > advance.
I'm not intimately familiar with GNU radio hardware and the experts here will hopefully correct me if needed, but I think you would face these issues: 1) The default FPGA logic doesn't offer a demodulation enable/disable, so you'd have to make some logic changes and rebuild. 2) Assuming the A/D converters on the LFTX and LFRX are > 8 bits and <= 16 bits, then the maximum sampling rate you could move over GbE would be around 60 MHz. Is that enough for your application? If you need faster rates but only in bursts (like a radar situation) then possibly some memory (block RAM) in the USRP2 FPGA could be used for buffers. I'm not sure how much is available... a build without demodulation would probably free up some mem. 3) Continuous streaming to HDD file could be difficult, or at least would require careful configuration of the HDD file system, real-time scheduling and other system considerations, and of course careful programming. -Jeff _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
