On Mon, Dec 10, 2007 at 01:28:38PM -0800, Fasika Alemayehu wrote: > Hi Eric, > > I also have got a similar situation. We are building a software > defined radio using GNU radio. We have a receiver front end to test > and analyze the performance of Wireless sensor nodes at 2.5GHz. The > module is similar with USRP but we are studying the differences > inorder to integrate the hardware with the gnuradio. I would really > appreciate if I can find any documentation about the details of the > signal transfer to/from the usrp and the usrp itself so that we can > see the difference between the USRP and our hardware. > > Best , > Fasika
There is no documentation outside of that in the code on this. However, it's pretty straight-forward. We talk to the USRP using 3 USB end points. EP0, the control endpoint, is used to load FX2 firmware and the FPGA .rbf file, low-level control of the daughterboards, setting control registers in the FPGA, and other misc operations. The list of operations and the arguments is in usrp/firmware/include/usrp_commands.h Received samples are sent from the FPGA via the FX2 over endpoint 6 using USB bulk transfers. Each USB packet is 512 bytes long, and the data in each packet is interleaved 16-bit little-endian I & Q pairs. I.e., I0, Q0, I1, Q1,... Transmit samples are sent in the same format over endpoint 2 using USB bulk tranfers. The schematics of the USRP are available as PDFs and gscheme source here: http://gnuradio.org/trac/browser/usrp-hw/trunk/USRP_REV_4_2 Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
